From owner-starship-design Wed Oct 16 06:10 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["761" "Wed" "16" "October" "1996" "08:06:13" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "22" "starship-design: Fractal robots." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id GAA24693 for starship-design-outgoing; Wed, 16 Oct 1996 06:10:11 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id GAA24628 for ; Wed, 16 Oct 1996 06:10:08 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA07954; Wed, 16 Oct 96 08:08:30 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI007851; Wed Oct 16 08:07:25 1996 Received: by most (4.1/SMI-4.1) id AA04269; Wed, 16 Oct 96 08:07:19 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma004246; Wed Oct 16 08:06:15 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA14105; Wed, 16 Oct 96 08:06:11 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 760 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Fractal robots. Date: Wed, 16 Oct 1996 08:06:13 -0500 Might be interesed in this. http://www.stellar.demon.co.uk/ Its about a concept called fractal robots. I.E. you build up large robots out of active 1 mil cubes that can manipulate one another along their surface and attach tools to their surface. Result works like the liquid metal terminator. Not a lot of tech details on the web site thou. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Wed Oct 16 06:38 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4323" "Wed" "16" "October" "1996" "08:35:55" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "90" "starship-design: Stellar drive?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id GAA05196 for starship-design-outgoing; Wed, 16 Oct 1996 06:38:26 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id GAA05172 for ; Wed, 16 Oct 1996 06:38:18 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA10308; Wed, 16 Oct 96 08:38:08 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI010188; Wed Oct 16 08:36:22 1996 Received: by most (4.1/SMI-4.1) id AA05057; Wed, 16 Oct 96 08:36:21 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma005041; Wed Oct 16 08:35:57 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA19259; Wed, 16 Oct 96 08:35:54 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 4322 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Stellar drive? Date: Wed, 16 Oct 1996 08:35:55 -0500 Stumbled across a web site in Britian describing an idea for a web site using asymetric micrpulses of magnatism. Its eiather very clever, or stuipid; and I'm to tired to figure out which. URL and cliping from intro follows. Kelly ----------------------------------------------------------------- http://www.stellar.demon.co.uk/stellar.htm A simple way to explain how a Stellar Drive works is to take two electromagnets made from copper wire with an air core and glue them back to back with an intervening plastic rod between them. The importance of not using an iron core (normally used to enhance the electromagnet's strength) is that with an air core, the electromagnets are not magnetic when switched off. Using copper for the wire and plastic for the intervening rod makes the whole assembly non-magnetic. If the electromagnets have magnetic cores, or if there are any significant magnetic materials nearby, the device will not work at the expected efficiencies. Figure 1 below shows the arrangement of the non-magnetic electromagnets and the plastic rod. When electromagnet one switches on, its field will propagate to electromagnet two. Before the field reaches electromagnet two, electromagnet one is switched off. Thus we get a travelling pulse of magnetic pulse that would eventually sweep past electromagnet two at the speed of light. As the pulse from electromagnet one arrives at electromagnet two, electromagnet two is switched on. Electromagnet two's field interacts with the passing field from electromagnet one and electromagnet two would be attracted to electromagnet one. (The arguments remain consistent whether the force is attraction or repulsion.) Figure 1 While the field from electromagnet one is interacting with electromagnet two, the rod feels a unidirectional push towards electromagnet one. In free space, the rod and electromagnet assembly would be accelerated unidirectionally. The situation is true while the field from electromagnet one is passing over electromagnet two. To create the equal and opposite force, the magnetic field from electromagnet two races to electromagnet one to interact with it to create the equal and opposite. But here it encounters a problem. Electromagnet one is switched off and since there is nothing magnetic there it cannot interact with it and so it must pass through it unaffected. The consequence of this escaping field is that we have created local momentum. Once all the fields have escaped the device, there is no way of cancelling the locally generated momentum. After the field from electromagnet two has passed through electromagnet one, the momentum generating cycle can be repeated. Electromagnet one is pulsed on and off again and as the field passes through electromagnet two, it is also pulsed on and off again generating more momentum. In theory, the device can keep on accelerating forever if there was a method for energizing the coils on and off in the incredibly short periods needed for the interactions to be observable. Because magnetic fields travel at the speed of light c, the energizing method must be very quick so as to generate the appropriate pulsed magnetic fields. The device has no moving parts, yet it generates thrust. If it were to be rotated clockwise ninety degrees and placed on a weighting machine (that has no magnetic components nearby) we would see the weight of the device lessening . The weight loss would be proportional to the amount of power fed to the electromagnets. Changing the phase at which the electromagnets are turned on and off and the frequency with which they are turned on and off will also register proportional thrust. The mark space ratio of the rectangular wave used to turn the electromagnets would also affect the thrust generation characteristics of the drive. ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Wed Oct 16 08:10 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["695" "Wed" "16" "October" "1996" "10:06:04" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "27" "starship-design: Saturn-V home page" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA27402 for starship-design-outgoing; Wed, 16 Oct 1996 08:10:30 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA27336 for ; Wed, 16 Oct 1996 08:10:20 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA16414; Wed, 16 Oct 96 10:10:08 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI016276; Wed Oct 16 10:07:56 1996 Received: by most (4.1/SMI-4.1) id AA07642; Wed, 16 Oct 96 10:07:50 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma007585; Wed Oct 16 10:06:05 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA03540; Wed, 16 Oct 96 10:06:03 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 694 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Saturn-V home page Date: Wed, 16 Oct 1996 10:06:04 -0500 If you didn't like the last web site. How about this one about the Saturn-V boosters. Kelly >-- >Charles E. (Chuck) Corway (http://www.calweb.com/~ccorway/) >Sacramento, California >Visit the Saturn V Launch Vehicle Web Page >at: http://www.calweb.com/~ccorway/saturn-v.htm >---- > ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Wed Oct 16 09:08 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["657" "Wed" "16" "October" "1996" "09:09:09" "-0700" "Steve VanDevender" "stevev@efn.org" nil "13" "starship-design: Stellar drive?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id JAA21175 for starship-design-outgoing; Wed, 16 Oct 1996 09:08:51 -0700 (PDT) Received: from haus.efn.org ([198.68.17.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with ESMTP id JAA21161 for ; Wed, 16 Oct 1996 09:08:49 -0700 (PDT) Received: from tzadkiel.efn.org (stevev@tzadkiel.efn.org [198.68.17.19]) by haus.efn.org (8.7.5/8.7.3) with ESMTP id JAA10177; Wed, 16 Oct 1996 09:12:43 -0700 (PDT) Received: (from stevev@localhost) by tzadkiel.efn.org (8.8.0/8.8.0) id JAA02419; Wed, 16 Oct 1996 09:09:09 -0700 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610161609.JAA02419@tzadkiel.efn.org> In-Reply-To: References: Precedence: bulk Reply-To: Steve VanDevender Content-Type: text Content-Length: 656 From: Steve VanDevender Sender: owner-starship-design To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Cc: starship-design@lists.uoregon.edu Subject: starship-design: Stellar drive? Date: Wed, 16 Oct 1996 09:09:09 -0700 [description of reactionless drive deleted] No one has ever built a _working_ reactionless drive that would work in zero-g and a vacuum. People have built gizmos that depend on the presence of air or friction to cause the appearance of a reactionless drive, but these gizmos only work when sitting on tables. The problem with a reactionless drive is that it would violate a lot of principles that physicists are pretty attached to, like conservation of momentum. A lot of the specious reasoning used in the explanation of so-called reactionless drives tends to ignore things like the momentum of electromagnetic radiation or the finite speed of light. From owner-starship-design Wed Oct 16 09:33 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3099" "Wed" "16" "October" "1996" "11:29:38" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "73" "Re: starship-design: Stellar drive?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id JAA06286 for starship-design-outgoing; Wed, 16 Oct 1996 09:33:46 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id JAA06174 for ; Wed, 16 Oct 1996 09:33:40 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA22427; Wed, 16 Oct 96 11:32:48 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI022264; Wed Oct 16 11:30:43 1996 Received: by most (4.1/SMI-4.1) id AA09612; Wed, 16 Oct 96 11:30:37 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma009592; Wed Oct 16 11:29:41 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA16738; Wed, 16 Oct 96 11:29:38 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 3098 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: Steve VanDevender Cc: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39), starship-design@lists.uoregon.edu Subject: Re: starship-design: Stellar drive? Date: Wed, 16 Oct 1996 11:29:38 -0500 At 9:09 AM 10/16/96, Steve VanDevender wrote: >[description of reactionless drive deleted] > >No one has ever built a _working_ reactionless drive that would work in >zero-g and a vacuum. People have built gizmos that depend on the >presence of air or friction to cause the appearance of a reactionless >drive, but these gizmos only work when sitting on tables. > >The problem with a reactionless drive is that it would violate a lot of >principles that physicists are pretty attached to, like conservation of >momentum. A lot of the specious reasoning used in the explanation of >so-called reactionless drives tends to ignore things like the momentum >of electromagnetic radiation or the finite speed of light. I know, it sounds like a dean drive or some such nonsence. The authors reply to that is that net momentum of is conserved globally, but not locally. I.E. the magnetics fields will cause a balencing counter force in general space, but not in the ship. (Authors clip added below.) So total energy would be conserved, just not locally. Using your box analogy. Its a big box, and other things in the box are accelerated with a balencing counter force. But that happens at a distence that needn't concern the ship. (He does by the way consider the finite speed of light, its a major element in the description.) So again, where is the hole in the concept? Kelly P.S. Is momentum always conserved? If you mix a mater and anti-mat partical, is their momentum carried over to the resulting photons? ----------------------------------------------------------------------------- Newtons Third Law of Motion The Stellar Drive would appear to be violating Newton's third law but if we look closely it does not violate Newton's laws. The escaping fields have pulling power. The fields escaping to the left have more pulling power than to the right because the fields escaping to the right have interacted with electromagnet two and thereby diminished its strength whereas the field escaping to the left is much stronger because it has not interacted with anything. These fields will terminate on distant objects and pull them cancelling the locally generated momentum. This part of the theory more than anything else allows the Stellar Drive to exist because from a theoretical point of view, Newton's third law is violated locally only to be cancelled globally which is perfectly acceptable science. If the device did break Newton's third law in its entirety, then virtually all of physics would need to re- written and most scientists would find it difficult to accept such a theory because of the counter evidence gathered from centuries of work. ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Thu Oct 17 08:24 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1853" "Thu" "17" "October" "1996" "17:24:27" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "44" "Re: starship-design: Stellar drive?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA06127 for starship-design-outgoing; Thu, 17 Oct 1996 08:24:50 -0700 (PDT) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA06036 for ; Thu, 17 Oct 1996 08:24:44 -0700 (PDT) Received: from hgl3-12.worldaccess.nl by driene.student.utwente.nl with SMTP id AA06071 (5.67b/IDA-1.5 for ); Thu, 17 Oct 1996 17:24:24 +0200 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610171524.AA06071@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1852 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: Re: starship-design: Stellar drive? Date: Thu, 17 Oct 1996 17:24:27 +0100 >At 9:09 AM 10/16/96, Steve VanDevender wrote: >>[description of reactionless drive deleted] >> >>No one has ever built a _working_ reactionless drive that would work in >>zero-g and a vacuum. People have built gizmos that depend on the >>presence of air or friction to cause the appearance of a reactionless >>drive, but these gizmos only work when sitting on tables. >> >>The problem with a reactionless drive is that it would violate a lot of >>principles that physicists are pretty attached to, like conservation of >>momentum. A lot of the specious reasoning used in the explanation of >>so-called reactionless drives tends to ignore things like the momentum >>of electromagnetic radiation or the finite speed of light. > > > >I know, it sounds like a dean drive or some such nonsence. The authors >reply to that is that net momentum of is conserved globally, but not >locally. I.E. the magnetics fields will cause a balencing counter force in >general space, but not in the ship. (Authors clip added below.) So total >energy would be conserved, just not locally. Using your box analogy. Its >a big box, and other things in the box are accelerated with a balencing >counter force. But that happens at a distence that needn't concern the >ship. (He does by the way consider the finite speed of light, its a major >element in the description.) > >So again, where is the hole in the concept? Magnetic fields is just EM-radiation, usually magnetic fields are very low frequency radiation, in some cases almost non-alternating. In any case photons are exchanged. So you could just as well (even better) use a laser to generate "local momentum". >P.S. >Is momentum always conserved? If you mix a mater and anti-mat >partical, is their momentum carried over to the resulting photons? Yes, not a tiny bit of momentum gets lost. Timothy From owner-starship-design Thu Oct 17 08:49 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2572" "Thu" "17" "October" "1996" "10:45:08" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "66" "Re: starship-design: Stellar drive?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA20971 for starship-design-outgoing; Thu, 17 Oct 1996 08:49:24 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA20781 for ; Thu, 17 Oct 1996 08:49:06 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA29443; Thu, 17 Oct 96 10:48:34 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI029185; Thu Oct 17 10:45:55 1996 Received: by most (4.1/SMI-4.1) id AA07313; Thu, 17 Oct 96 10:45:46 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma007295; Thu Oct 17 10:45:09 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA22520; Thu, 17 Oct 96 10:45:06 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 2571 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Stellar drive? Date: Thu, 17 Oct 1996 10:45:08 -0500 At 5:24 PM 10/17/96, Timothy van der Linden wrote: >>At 9:09 AM 10/16/96, Steve VanDevender wrote: >>>[description of reactionless drive deleted] >>> >>>No one has ever built a _working_ reactionless drive that would work in >>>zero-g and a vacuum. People have built gizmos that depend on the >>>presence of air or friction to cause the appearance of a reactionless >>>drive, but these gizmos only work when sitting on tables. >>> >>>The problem with a reactionless drive is that it would violate a lot of >>>principles that physicists are pretty attached to, like conservation of >>>momentum. A lot of the specious reasoning used in the explanation of >>>so-called reactionless drives tends to ignore things like the momentum >>>of electromagnetic radiation or the finite speed of light. >> >> >> >>I know, it sounds like a dean drive or some such nonsence. The authors >>reply to that is that net momentum of is conserved globally, but not >>locally. I.E. the magnetics fields will cause a balencing counter force in >>general space, but not in the ship. (Authors clip added below.) So total >>energy would be conserved, just not locally. Using your box analogy. Its >>a big box, and other things in the box are accelerated with a balencing >>counter force. But that happens at a distence that needn't concern the >>ship. (He does by the way consider the finite speed of light, its a major >>element in the description.) >> >>So again, where is the hole in the concept? > >Magnetic fields is just EM-radiation, usually magnetic fields are very low >frequency radiation, in some cases almost non-alternating. In any case >photons are exchanged. >So you could just as well (even better) use a laser to generate "local >momentum". Thats true. Even this guy admits that the system is estimated to be 1% efficent (thou he thinks that might be improved with better systems). >>P.S. >>Is momentum always conserved? If you mix a mater and anti-mat >>partical, is their momentum carried over to the resulting photons? > >Yes, not a tiny bit of momentum gets lost. Hum... Can this be used to direct the resulting particals/photons? > >Timothy Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Thu Oct 17 08:58 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1290" "Thu" "17" "October" "1996" "10:58:16" "-0500" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "37" "starship-design: Stellar drive (possible hole)" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA27356 for starship-design-outgoing; Thu, 17 Oct 1996 08:58:23 -0700 (PDT) Received: from mhub0.tc.umn.edu (mhub0.tc.umn.edu [128.101.131.50]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA27331 for ; Thu, 17 Oct 1996 08:58:21 -0700 (PDT) Received: from maroon.tc.umn.edu by mhub0.tc.umn.edu; Thu, 17 Oct 96 10:58:18 -0500 Received: by maroon.tc.umn.edu; Thu, 17 Oct 96 10:58:18 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f In-Reply-To: <199610171524.AA06071@driene.student.utwente.nl> Message-ID: MIME-Version: 1.0 Precedence: bulk Reply-To: Kevin C Houston Content-Type: TEXT/PLAIN; charset=US-ASCII Content-Length: 1289 From: Kevin C Houston Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Stellar drive (possible hole) Date: Thu, 17 Oct 1996 10:58:16 -0500 (CDT) > So you could just as well (even better) use a laser to generate "local > momentum". but i thought that the photons weren't exchanged in a magnetic field unless there was something to react with. but the main problem I see with this drive is when the magnetic field reacts with the supposedly "inert" other end. in the description, it was said that you have two coils separated by long distance. and only one of them is on at a time (roughly speaking) but when the second(drive end) switches on, it's magnetic field _will_ react with the unpowered coil at the other end. specificly, it will generate an electrical current. > > >P.S. > >Is momentum always conserved? If you mix a mater and anti-mat > >partical, is their momentum carried over to the resulting photons? > > Yes, not a tiny bit of momentum gets lost. > So if I have 1 Kg of Matter moving in the +x direction, and it hits 1 Kg of anti-matter moving in the -x direction, what happens to the photons? If the move in any direction, then you have violated conservation of momentum. If you say they move in all directions evenly, (which is likely) then what happens if the two mass streams (matter and anti-matter) approach from a 45 degree angle. does the light shine in one direction preferentialy? Kevin From owner-starship-design Thu Oct 17 10:54 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1859" "Thu" "17" "October" "1996" "10:54:58" "-0700" "Steve VanDevender" "stevev@efn.org" nil "43" "starship-design: Stellar drive (possible hole)" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id KAA18730 for starship-design-outgoing; Thu, 17 Oct 1996 10:54:42 -0700 (PDT) Received: from haus.efn.org (haus.efn.org [198.68.17.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with ESMTP id KAA18716 for ; Thu, 17 Oct 1996 10:54:40 -0700 (PDT) Received: from tzadkiel.efn.org (stevev@tzadkiel.efn.org [198.68.17.19]) by haus.efn.org (8.7.5/8.7.3) with ESMTP id KAA17342; Thu, 17 Oct 1996 10:58:35 -0700 (PDT) Received: (from stevev@localhost) by tzadkiel.efn.org (8.8.0/8.8.0) id KAA06030; Thu, 17 Oct 1996 10:54:58 -0700 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610171754.KAA06030@tzadkiel.efn.org> In-Reply-To: References: <199610171524.AA06071@driene.student.utwente.nl> Precedence: bulk Reply-To: Steve VanDevender Content-Type: text Content-Length: 1858 From: Steve VanDevender Sender: owner-starship-design To: Kevin C Houston Cc: starship-design@lists.uoregon.edu Subject: starship-design: Stellar drive (possible hole) Date: Thu, 17 Oct 1996 10:54:58 -0700 Kevin C. Houston writes: > > >P.S. > > >Is momentum always conserved? If you mix a mater and anti-mat > > >partical, is their momentum carried over to the resulting photons? > > > > Yes, not a tiny bit of momentum gets lost. > > So if I have 1 Kg of Matter moving in the +x direction, > and it hits 1 Kg of anti-matter moving in the -x direction, > what happens to the photons? If the move in any direction, > then you have violated conservation of momentum. What, you think all the photons and pions and stuff just _hover_ around the ex-matter and ex-antimatter to conserve momentum? Here is your mantra for this week, Kevin: "Momentum is a vector quantity. Momentum is conserved as a vector quantity." Meditate on it for at least one hour a day. Take the _vector_ sum of the momentum vectors of the matter and antimatter chunks, and it will also be the _vector_ sum of the momentum vectors of all the photons and elementary particles that fly out of the annihilation. > If you say they move in all directions evenly, (which is likely) > then what happens if the two mass streams (matter and anti-matter) > approach from a 45 degree angle. does the light shine in one > direction preferentialy? Yes, if you are in the frame where the matter and antimatter are seen to approach at that angle. The observed net momentum of all the reaction products is the same as the net momentum of the matter and antimatter chunks. On the other hand, someone moving with the chunks in such a way that he sees the center of momentum at rest will see light emitted in all directions equally, so that the net momentum of all the light is also a zero vector. What's so hard to get about this? Momentum is a vector. Momentum is conserved as a vector. The net momentum of a system does not change no matter how the parts of the system interact. From owner-starship-design Sat Oct 19 07:55 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["602" "Sat" "19" "October" "1996" "16:55:39" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "19" "Re: starship-design: Stellar drive?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id HAA29854 for starship-design-outgoing; Sat, 19 Oct 1996 07:55:52 -0700 (PDT) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id HAA29841 for ; Sat, 19 Oct 1996 07:55:38 -0700 (PDT) Received: from hgl3-12.worldaccess.nl by driene.student.utwente.nl with SMTP id AA06201 (5.67b/IDA-1.5 for ); Sat, 19 Oct 1996 16:55:36 +0200 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610191455.AA06201@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 601 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: Re: starship-design: Stellar drive? Date: Sat, 19 Oct 1996 16:55:39 +0100 Kelly replied: >> Now that I have said that, if anyone finds a method of >> shielding a magnetic field, it might be usable. Even >> better, shielding is but the first step to >> FOCUSING which will boost the efficiency and power >> output enormously. > >> L. Parker > >Its called a Faraday cage. Basicly a electrically conductive outer liner >with no significant gaps for the fields to get through. Well, a Faraday cage has it's limits, it may decrease the fieldstrength but depending on the structure (thickness, conductivity, meshsize) of the wall it leaves through a certain amount. Timothy From owner-starship-design Sat Oct 19 07:56 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["631" "Sat" "19" "October" "1996" "16:56:23" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "20" "Re: starship-design: Stellar drive (possible hole)" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id HAA29892 for starship-design-outgoing; Sat, 19 Oct 1996 07:56:28 -0700 (PDT) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id HAA29876 for ; Sat, 19 Oct 1996 07:56:23 -0700 (PDT) Received: from hgl3-12.worldaccess.nl by driene.student.utwente.nl with SMTP id AA06248 (5.67b/IDA-1.5 for ); Sat, 19 Oct 1996 16:56:20 +0200 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610191456.AA06248@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 630 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: Re: starship-design: Stellar drive (possible hole) Date: Sat, 19 Oct 1996 16:56:23 +0100 Kevin replied: >> So you could just as well (even better) use a laser to generate "local >> momentum". > >but i thought that the photons weren't exchanged in a magnetic field >unless there was something to react with. If you read my words literally, there is indeed no exchange if there is nothing to exchange with, however charge particles sent out and receive (virtual) photons all the time. Since magnetic fields are the result of relativistic effects (mainly velocity addition) on moving charges, there are also photons sent out. About conserving momentum, I believe Steve has already answered your questions. Timothy From owner-starship-design Sat Oct 19 16:46 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["141" "Sat" "19" "October" "1996" "19:46:21" "-0400" "KellySt@aol.com" "KellySt@aol.com" nil "5" "starship-design: Alien World Artical" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id QAA01499 for starship-design-outgoing; Sat, 19 Oct 1996 16:46:52 -0700 (PDT) Received: from emout11.mail.aol.com (emout11.mx.aol.com [198.81.11.26]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id QAA01489 for ; Sat, 19 Oct 1996 16:46:49 -0700 (PDT) Received: by emout11.mail.aol.com (8.6.12/8.6.12) id TAA16219 for starship-design@lists.uoregon.edu; Sat, 19 Oct 1996 19:46:21 -0400 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961019194618_1179636002@emout11.mail.aol.com> Precedence: bulk Reply-To: KellySt@aol.com Content-Type: text Content-Length: 140 From: KellySt@aol.com Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Alien World Artical Date: Sat, 19 Oct 1996 19:46:21 -0400 Check out the November '96 Analog Magazine. A groups been working on a alien world ecology senario. The artical looks interesting. Kelly From owner-starship-design Sat Oct 19 16:46 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["939" "Sat" "19" "October" "1996" "19:46:23" "-0400" "KellySt@aol.com" "KellySt@aol.com" nil "27" "Re: starship-design: Stellar drive?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id QAA01514 for starship-design-outgoing; Sat, 19 Oct 1996 16:46:54 -0700 (PDT) Received: from emout15.mail.aol.com (emout15.mx.aol.com [198.81.11.41]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id QAA01498 for ; Sat, 19 Oct 1996 16:46:51 -0700 (PDT) Received: by emout15.mail.aol.com (8.6.12/8.6.12) id TAA08907 for starship-design@lists.uoregon.edu; Sat, 19 Oct 1996 19:46:23 -0400 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961019194622_1414315170@emout15.mail.aol.com> Precedence: bulk Reply-To: KellySt@aol.com Content-Type: text Content-Length: 938 From: KellySt@aol.com Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: Re: starship-design: Stellar drive? Date: Sat, 19 Oct 1996 19:46:23 -0400 >Kelly replied: >>> Now that I have said that, if anyone finds a method of >>> shielding a magnetic field, it might be usable. Even >>> better, shielding is but the first step to >>> FOCUSING which will boost the efficiency and power >>> output enormously. >> >>> L. Parker >> >> Its called a Faraday cage. Basicly a electrically >> conductive outer liner with no significant gaps >> for the fields to get through. > > Well, a Faraday cage has it's limits, it may decrease > the fieldstrength but depending on the structure > (thickness, conductivity, meshsize) of the wall > it leaves through a certain amount. > > Timothy Ok, be that way. ;p Coat the thing with a super conductor. What gets through you can convert back to electricity. A better question is would the thing work, and would it actually be efficent enough to be usful. To my surprize 1 is sounding likely. On the other hand. 2 sounds like a no go. Kelly From owner-starship-design Sat Oct 19 18:04 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1152" "Sat" "19" "October" "1996" "18:05:04" "-0700" "Steve VanDevender" "stevev@efn.org" nil "25" "Re: starship-design: Stellar drive?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id SAA25796 for starship-design-outgoing; Sat, 19 Oct 1996 18:04:43 -0700 (PDT) Received: from haus.efn.org (haus.efn.org [198.68.17.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with ESMTP id SAA25786 for ; Sat, 19 Oct 1996 18:04:41 -0700 (PDT) Received: from tzadkiel.efn.org (stevev@cisco-ts11-line9.uoregon.edu [128.223.150.124]) by haus.efn.org (8.7.5/8.7.3) with ESMTP id SAA10959; Sat, 19 Oct 1996 18:08:38 -0700 (PDT) Received: (from stevev@localhost) by tzadkiel.efn.org (8.8.2/8.8.2) id SAA08119; Sat, 19 Oct 1996 18:05:04 -0700 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610200105.SAA08119@tzadkiel.efn.org> In-Reply-To: <961019194622_1414315170@emout15.mail.aol.com> References: <961019194622_1414315170@emout15.mail.aol.com> Precedence: bulk Reply-To: Steve VanDevender Content-Type: text Content-Length: 1151 From: Steve VanDevender Sender: owner-starship-design To: KellySt@aol.com Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Stellar drive? Date: Sat, 19 Oct 1996 18:05:04 -0700 KellySt@aol.com writes: > >> Its called a Faraday cage. Basicly a electrically > >> conductive outer liner with no significant gaps > >> for the fields to get through. > > > > Well, a Faraday cage has it's limits, it may decrease > > the fieldstrength but depending on the structure > > (thickness, conductivity, meshsize) of the wall > > it leaves through a certain amount. > > > > Timothy > > Ok, be that way. ;p Coat the thing with a super conductor. What gets > through you can convert back to electricity. A better question is would the > thing work, and would it actually be efficent enough to be usful. To my > surprize 1 is sounding likely. On the other hand. 2 sounds like a no go. Superconductors stop being superconductors in strong magnetic fields. This is also a fundamental limit on the amount of current a superconducting wire can carry, as above a certain amount of current the magnetic field created by the current breaks down the superconductivity. In the most entertaining cases this can result in the superconducting wire vaporizing suddenly from the current dissipating through a now resistive wire. From owner-starship-design Sun Oct 20 22:43 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6847" "Mon" "21" "October" "1996" "00:48:16" "-0500" "Kevin Houston" "hous0042@maroon.tc.umn.edu" nil "156" "starship-design: Re: Solar sail breaking" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id WAA11575 for starship-design-outgoing; Sun, 20 Oct 1996 22:43:05 -0700 (PDT) Received: from mhub1.tc.umn.edu (mhub1.tc.umn.edu [128.101.131.51]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id WAA11563 for ; Sun, 20 Oct 1996 22:43:03 -0700 (PDT) Received: from maroon.tc.umn.edu by mhub1.tc.umn.edu; Mon, 21 Oct 96 00:43:02 -0500 Received: from pub-1-d-55.dialup.umn.edu by maroon.tc.umn.edu; Mon, 21 Oct 96 00:42:58 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <326B0E9F.4C52@maroon.tc.umn.edu> Organization: URLy Bird Productions http://www.urly-bird.com/prices.html X-Mailer: Mozilla 3.0 (Win95; U) MIME-Version: 1.0 References: <199610202117_MC1-B1A-5853@compuserve.com> Content-Transfer-Encoding: 7bit Precedence: bulk Reply-To: "Kevin \"Tex\" Houston" Content-Type: text/plain; charset=us-ascii Content-Length: 6846 From: "Kevin \"Tex\" Houston" Sender: owner-starship-design To: Starship design group CC: Nick Tosh <101765.2200@compuserve.com> Subject: starship-design: Re: Solar sail breaking Date: Mon, 21 Oct 1996 00:48:16 -0500 Nick Tosh wrote: > > Hello everybody. > > From what I've gathered from reading past mailings, stopping a starship > powered by a Sol based particle/EM rad beam is a major problem. Rex has analysed this problem and a solution has been found. While Rex claims it's not very efficient, he does prove that it is theoretically sound, and violates no physical laws. The idea is my old Microwave Augmented Rocket System (MARS). A ship departs earth with tanks full of Reaction Mass (RM), and accelerates away from earth using a microwave sail. At the turn-around point, (not necessarily the halfway point), the ship converts the energy from the microwaves into electricity, and uses that to accelerate the RM to a hefty fraction of C. This has been shown to yeild more momentum from the "engine", than the ship would absorb from the sail. Mass ratios and exhaust velocities, depend heavily upon conversion ratios (converting recieved microwave energy to kinetic energy in the exhaust) Here is what Rex had to say on this subject. --------begin included text------------------------------- The effects of reduced conversion efficiency (eta less than 1) on required exhaust velocity, final sail furl and, most importantly, required mass ratio are given in the table below: eta exhaust velocity final sail furl mass ratio 1.0 0.883 0.160 9.41 0.9 0.849 0.105 15.44 0.8 0.809 0.060 29.05 0.7 0.760 0.029 67.57 Producing high efficiency of conversion from received power to exhaust power may be as challenging (and as crucial to the success of the concept) as constructing the emitter or the sail. ----------end included text------------------------------- So even a fairly high efficiency of .7 means a mass ratio of 68. This is not too bad, considering some of the other mass ratios I've seen bandied about. (114 for really good anti matter ship) Now the problem here is that current linear accelerators are not very efficient, according to Rex. He states that at best, they are only about 1% effiecient. In a letter I sent to Tim, I said that I doubted current lineac efficiencies could be used to model practical maximums. Consider the following senario: ---------------begin included text------------------------------ Junior designer comes into directors office and says "Hey Boss, I just figured out how we can boost the efficiency of our main accelerator to nearly 75%!" Senior designer "Really, how much electricity will this save?" Junior desinger "5000 Megawatt-hours per year." Senior designer "And how much will these improvements cost?" Junior designer "Only 25 million dollars, well within our budget." Senior designer "Since we pay about 5 cents per kilowatt hour, your improvements will save 250,000 dollars a year, but it will take 25 million to implement it. Thus it will take 100 years to pay for the improvement." Junior designer "Oh, I never looked at it from that point before." Senior designer "That's why I'm the boss" Of course, the junior designer, if he was any good would have figured the payback time himself, and saved himself the embarassment of this kind of exchange. So I'm not sure that accelerator efficiency here on earth is that good of a gauge of maximum possible. -----------------end included text------------------------------ Another problem with this design has been pointed out by Kelly. I've said that an advantage with this system is that while in flight we done need any spinning sections. Kelly's point is that this would have an adverse effect on the crew. Because the power beam from earth is constant (to minimize hassle), and the ship is going to approach light-speed (.9331 of C) then something has to give. That something is the precieved acceleration felt by the crew. This will fall to ~1/7 earth normal near the turn-around point. As the ship begins to decelerate, the "gravity" will again climb toward earth normal. Kelly fears that extended time at less than 1 Gee will have an adverse effect on the crew. I disagree with this because the change will be relatively slow. Even after Six months at Zero Gee, Shannon Lucid was able to walk out of the shuttle after it landed (much to the dismay of NASA doctors to be sure.) and this was an abrupt change, a slow build up of "gravity" should be easy to adapt to, especially if a strict exercise program is instituted. hell, we always wondered what the crew would do with their spare time, now we know. They'll be exercising! While it is true that we will need a spinning section while we are in the target system, we should not need one during the flight. So again, I propose the following ship configuration: Consider the in-flight section to be like a soda can, and the habitat section to be like a larger soup can. While accelerating toward TC, the crew resides in the soda can, at the turn-around point, the soda can is extracted from the soup can, turned around, and put back in. Upon reaching TC, the crew moves into the soup can, which is spun up to provide the required gravity. All of the exploration equipment is stored in the soup can. The soda can is now free to be rehabed, and the soup can acts like a dry dock. When the time comes to leave, the soda can is what returns. the soup can stays behind as a base, and if for some strange reason, we decide to leave a permanent force behind, then we have a place for them to live. if not, then everyone gets back into soda can and heads for earth. The return Module uses a microwave Sail to accelerate away from TC, and uses Earth's Masers to decelerate. I really think this is the best design we've come up with yet. Aside from the cost and the political will issues, none of this technology is beyond our capability. We know how to make solar collectors, masers, linear accelerators and closed system ecologies. The question remains, can we build them large enough, precise enough, efficient enough and will they last long enough to make it to TC and back agin. But then, these are engineering problems, not physics problems. In contrast, the only other viable alternatives (from a physics standpoint) is a fusion-sail hybrid (Kelly's fuel-sail) an anti-matter rocket, and the argosy concept. The fuel sail and the anti-matter rocket both require technology that we do not yet posses, and may have trouble with by 2050 or even 2100. The argosy concept would take centuries to get to target star. The MARS remains the Fastest, lightest, and easiest (relatively speaking) ship to build. Sincerly, -- Kevin "Tex" Houston http://umn.edu/~hous0042/index.html From owner-starship-design Mon Oct 21 07:04 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4993" "Mon" "21" "October" "1996" "09:00:43" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "102" "starship-design: Re: Solar sail breaking" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id HAA02639 for starship-design-outgoing; Mon, 21 Oct 1996 07:04:43 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id HAA02608 for ; Mon, 21 Oct 1996 07:04:33 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA11597; Mon, 21 Oct 96 09:04:11 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI011516; Mon Oct 21 09:02:39 1996 Received: by most (4.1/SMI-4.1) id AA06103; Mon, 21 Oct 96 09:02:28 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma006049; Mon Oct 21 09:00:45 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA23358; Mon, 21 Oct 96 09:00:41 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 4992 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: Nick Tosh <101765.2200@compuserve.com> Cc: "[unknown]" , "[unknown]" , "[unknown]" , "[unknown]" , "[unknown]" , Phillip Bakelaar , "Kevin C. Houston" , Zenon Kulpa , David Levine , Timothy van der Linden , "L. Clayton Parker" , Kelly Starks , Steve VanDevender Subject: starship-design: Re: Solar sail breaking Date: Mon, 21 Oct 1996 09:00:43 -0500 At 8:49 PM 10/20/96, Nick Tosh wrote: >Hello everybody. > >You may not remember me - I haven't contributed anything for nearly a year >now. I had computer problems that kept me off the net for over six months, >and for various reasons I've been very busy since. Anyway, I'd like to >'rejoin' LIT. I'm a student in England, and I'll be going to study physics >at university next year. You already have me on your mailing list, so I'm >pretty much up to date. Hi Nick, welcome back. Are you on the starship-design@lists.uoregon.edu List? Its become our central list rather then addressing each other individually. >>From what I've gathered from reading past mailings, stopping a starship >powered by a Sol based particle/EM rad beam is a major problem. The (fairly >obvious) idea that occurred to me was that a solar sail would be much more >attractive as a braking device when approaching a target star at high >relativistic speed than as an accelerating device for leaving Sol. The >doppler shifts that are such a pain in the latter case, or for the Sol >based microwave beam, become a significant help if the sail is moving >towards the energy source (i.e. Tau Ceti, or even better, the multi-star >-triple?- Centauri system). If the starship is moving towards the target >system at velocity v, expressed as a fraction of c, then the the impulse >imparted per reflected incident photon of frequency Fo measured in the >star's frame is: > _____ >2(h Fo) / 1 + v >---------- / -------- (by the way, do any of you use Mathcad? I hate >typing out maths like this and would much rather e-mail Mathcad files). > c \/ 1 - v Sorry. Macs come with a free (oldish) version of Mathmatica. Would the files be compatible? >(The photons is reflected, so its change in momentum is twice the magnitude >of its initial Doppler shifted momentum. I think that the reflected photon >is of the same -shifted- frequency of the incident photon, since otherwise >the solar sail would have to absorb more energy than it radiated, and this >surely cannot be a theoretical requirement; in any case, how would the sail >know what the 'proper' non-shifted frequency was meant to be?) The above >expression obviously shows that the impulse imparted to the ship by each >photon approaches infinity as the velocity of the ship approaches 1c. >Unfortunately, the mass of the ship also approaches infinity, so the >decellerating effect remains finite. However, the mass increase factor is 1 >/ sqrt(1-v^2), while the impulse increase factor is sqrt[(1+v)/(1-v)]. If >we divide the impulse factor by the mass factor we get (1+v). So the >impulse per photon increases faster than the mass does - the decelleration >(in ship's frame) provided by the sail increases with speed. The limiting >case, v approaching 1, results in double the 'rest' decelleration. Since >for most other forms of propulsion relativistic effects make decelleration >more difficult at higher speeds, might not a sail be a useful additional >'brake' for the starship? (I wouldn't even suggest it as the only one). The >main disadvantage of this system would be that to reap the benefit of the >sails high velocity performance, the starship would have to still be moving >very fast while near enough to the target star to get a fairly intense >photon flux. Chances are it couldn't slow down in time. Some compromise >would be necessary. Could the ship purposely overshoot the star, so as to >get some big delta-V from the sail while VERY close to the star? As it >passed by, it could furl the sail to avoid getting accelerated away from >the star (I think I like that idea. Has it been considered before? Making >such a long journey even a little longer is an odd idea, but it could be >useful. I'll do some maths on it later). The stellar radiation would be too breif and weak to help us much. >I need some help on the following point. Does time dilation result in the >high velocity starship intercepting more photons per unit time than an >observer in orbit around the star sees the star emit in the ship's >direction? Does relativity really increase both the impulse gained from >each photon AND the photon flux (in the ship's frame)? I don't know enough >to answer this, and I'm too tired to think about it now. If the aswer to >this is yes, than I think some serious modelling of the sail brake should >be done immediately. Please could someone answer this for me as soon as >poss. Don't look at me. I'm the fusion guy. ;) >Could people tell me if this mail gets through? > >Nick Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Mon Oct 21 07:12 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3475" "Mon" "21" "October" "1996" "09:08:01" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "73" "starship-design: Re: Stellar Drive" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id HAA07537 for starship-design-outgoing; Mon, 21 Oct 1996 07:12:54 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id HAA05447 for ; Mon, 21 Oct 1996 07:11:38 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA12029; Mon, 21 Oct 96 09:10:26 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI011853; Mon Oct 21 09:08:34 1996 Received: by most (4.1/SMI-4.1) id AA06236; Mon, 21 Oct 96 09:08:24 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma006231; Mon Oct 21 09:08:01 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA24524; Mon, 21 Oct 96 09:07:59 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 3474 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: Nick Tosh <101765.2200@compuserve.com> Subject: starship-design: Re: Stellar Drive Date: Mon, 21 Oct 1996 09:08:01 -0500 At 8:48 PM 10/20/96, Nick Tosh wrote: >Interesting idea. Is the physics really OK on this one? It sounds dodgy. I >don't follow the author's attempt to keep Newton's third. What if there >were no charged matter in the direction of the escaping fields? If there >were charged matter, would it not make a difference if it was mainly >negative or positive? The magnetic forces would be in opposite directions >for opposite charges. If there were no charged matter moving relative to >the electromagnets, there would again be no possibility of future magnetic >forces making up lost momentum. Does the concept depend on the statistical >distribution of charge and velocity throughout the universe surrounding the >magic drive? Surely the principle of reaction is not statistical in the >sense thermodynamics is. There has to be charged matter out there sooner or later. So the total momentum of the system (I>E. the universe) is conseved. Unfortunatly it sounds like the bulk of the power would go to creating magnetic fields blasting out into nowhere. So we have a theoretically possible drive system, thats not very usefully. Pity, It could give Kevins MARS system a big boost? ;) >I have a few other points. Timothy wrote: > >>Magnetic fields is just EM-radiation, usually magnetic fields are very low >>frequency radiation, in some cases almost non-alternating. In any case >>photons are exchanged. >>So you could just as well (even better) use a laser to generate "local >>momentum". > >How would you make a laser pull? Lasers, indeed all real photons, only >push. The force on the target would be cancelled by the reaction to the >laser emission in the emitter, and the system would experince no net force. >With pulling virtual photons, the idea seems to imply an odd free lunch - >the action and reaction are in the same direction. But we still pay for >it... The photon presure from the laser would push the ship. >I think Kevin made a good point about the second electromagnet's field >interacting with the first electromagnet by inducung a current in it. I >don't think that shielding it with a superconductor would help - a current >would be induced in the superconductor, and you would still have your >unwanted reaction force. It would be like a bar magnet hovering over the >eddy currents it produces in a superconductor. > >My final point is that if the system doesn't violate Newton's Third Law, >what's the point of it? Its not really a 'stellar drive' (how did >reactionless drives get that name?) at all. I assume the point of a >reactionless drive is to save a starship from using up its energy on >reaction mass - one would prefer that it convert all its stored energy into >KE for itself. But if the magnetic fields created eventually do accelerate >a distant 'reaction mass', no energy has been saved. So is the concept >really helpful for us? > >Just out of interest, is there any way of focussing virtual photons to >concentrate a magnetic field in one direction? I doubt it's possible >without making the photons real first. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Mon Oct 21 07:27 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1099" "Mon" "21" "October" "1996" "16:27:40" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "28" "Re: starship-design: Stellar drive?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id HAA14662 for starship-design-outgoing; Mon, 21 Oct 1996 07:27:57 -0700 (PDT) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id HAA14648 for ; Mon, 21 Oct 1996 07:27:51 -0700 (PDT) Received: from hgl3-4.worldaccess.nl by driene.student.utwente.nl with SMTP id AA23251 (5.67b/IDA-1.5 for ); Mon, 21 Oct 1996 16:27:31 +0200 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610211427.AA23251@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1098 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: Re: starship-design: Stellar drive? Date: Mon, 21 Oct 1996 16:27:40 +0100 L. Parker wrote: >Well, I don't suppose it would be fair if I didn't at least offer an idea >for a solution. I haven't ever heard of a Faraday cage, and I am not sure >if it works or how strong of a field it would have to generate in order to >work, but how about if your second field was the shield also? Shaped kind >of like this: > \ > O | > / > >Just a thought... A Faraday cage is a passive thing, it does not generate a field, it converts the EM-radiation into an electrical current. It is not a complicated thing, it is merely a wiremesh in the form of a cage (round, square) it's shape does not matter much, as long as it is closed. The general theory is that as soon as a difference in fieldstrength is present between two points of the cage, the electric current will resolve that. The size of the mesh is important, the smaller the mesh size, the better it protects against high frequencies. By the way, why do we need alternating magnetic fields, or are constant magnetic fields possible too? Timothy From owner-starship-design Mon Oct 21 07:55 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["820" "Mon" "21" "October" "1996" "09:55:12" "-0500" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "26" "starship-design: Re: LIT site 2" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id HAA20461 for starship-design-outgoing; Mon, 21 Oct 1996 07:55:17 -0700 (PDT) Received: from mhub0.tc.umn.edu (mhub0.tc.umn.edu [128.101.131.50]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id HAA20428 for ; Mon, 21 Oct 1996 07:55:14 -0700 (PDT) Received: from maroon.tc.umn.edu by mhub0.tc.umn.edu; Mon, 21 Oct 96 09:55:15 -0500 Received: by maroon.tc.umn.edu; Mon, 21 Oct 96 09:55:14 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f In-Reply-To: Message-ID: MIME-Version: 1.0 Precedence: bulk Reply-To: Kevin C Houston Content-Type: TEXT/PLAIN; charset=US-ASCII Content-Length: 819 From: Kevin C Houston Sender: owner-starship-design To: Starship design group cc: Nick Tosh <101765.2200@compuserve.com> Subject: starship-design: Re: LIT site 2 Date: Mon, 21 Oct 1996 09:55:12 -0500 (CDT) On Mon, 21 Oct 1996, Kelly Starks x7066 MS 10-39 wrote about LIT2: > Would certain persons working on MARS and Argosey ship designs get their > stuff written up? ;) EEEP! Ooops, sorry about that. I'll get on it right away. If anyone wants access to the URLy-bird site, Just E-mail me for the username/password. since I can't offer eneryone a different password, I must know who's got access. so please, if I give you the password, don't give it to anyone else, make them come through me. If you don't think you'll be doing that much in the site, then please don't ask for the password. Also, I've had a few questions about listserv. Since Steve's doing such a good job with the darkwing listsever, I wouldn't dream of messing that up. so my answer is no; no listserv out of urly-bird. Later Kevin From owner-starship-design Mon Oct 21 08:12 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6151" "Mon" "21" "October" "1996" "10:12:03" "-0500" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "144" "Re: starship-design: Re: Solar sail breaking" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA26994 for starship-design-outgoing; Mon, 21 Oct 1996 08:12:10 -0700 (PDT) Received: from mhub1.tc.umn.edu (mhub1.tc.umn.edu [128.101.131.51]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA26938 for ; Mon, 21 Oct 1996 08:12:07 -0700 (PDT) Received: from maroon.tc.umn.edu by mhub1.tc.umn.edu; Mon, 21 Oct 96 10:12:06 -0500 Received: by maroon.tc.umn.edu; Mon, 21 Oct 96 10:12:05 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f In-Reply-To: Message-ID: MIME-Version: 1.0 Precedence: bulk Reply-To: Kevin C Houston Content-Type: TEXT/PLAIN; charset=US-ASCII Content-Length: 6150 From: Kevin C Houston Sender: owner-starship-design To: Starship design group cc: Nick Tosh <101765.2200@compuserve.com> Subject: Re: starship-design: Re: Solar sail breaking Date: Mon, 21 Oct 1996 10:12:03 -0500 (CDT) On Mon, 21 Oct 1996, Kelly Starks x7066 MS 10-39 wrote: > At 12:48 AM 10/21/96, Kevin \"Tex\" Houston wrote: > > > >The idea is my old Microwave Augmented Rocket System (MARS). A ship > >departs earth with tanks full of Reaction Mass (RM), and accelerates > >away from earth using a microwave sail. > > > >At the turn-around point, (not necessarily the halfway point), the > >ship converts the energy from the microwaves into electricity, and > >uses that to accelerate the RM to a hefty fraction of C. > > > >Here is what Rex had to say on this subject. > > > >--------begin included text------------------------------- > >The effects of reduced conversion efficiency (eta less > >than 1) on required exhaust velocity, final sail furl and, most > >importantly, required mass ratio are given in the table below: > > > > eta exhaust velocity final sail furl mass ratio > > 1.0 0.883 0.160 9.41 > > 0.9 0.849 0.105 15.44 > > 0.8 0.809 0.060 29.05 > > 0.7 0.760 0.029 67.57 > > > >Producing high efficiency of conversion from received power to > >exhaust power may be as challenging (and as crucial to the > >success of the concept) as constructing the emitter or the sail. > >----------end included text------------------------------- > > > >So even a fairly high efficiency of .7 means a mass ratio of 68. > >This is not too bad, considering some of the other mass ratios I've > >seen bandied about. (114 for really good anti matter ship) > > What are the cruise speeds and flight times that you can get to with this? There is no cruise per se. The ship is a constant thrust mission, but the thrust steadily decreases throughout the mission. then builds up again. top speed is .93 C flight time is 8 years for the crew, and 15 years for earth. > Kevin: > >Another problem with this design has been pointed out by Kelly. > >I've said that an advantage with this system is that while in flight > >we done need any spinning sections. Kelly's point is that this would > >have an adverse effect on the crew. > > > >Because the power beam from earth is constant (to minimize hassle), > >and the ship is going to approach light-speed (.9331 of C) then > >something has to give. That something is the precieved acceleration > >felt by the crew. This will fall to ~1/7 earth normal near the > >turn-around point. As the ship begins to decelerate, the "gravity" > >will again climb toward earth normal. > > > >Kelly fears that extended time at less than 1 Gee will have an adverse > >effect on the crew. I disagree with this because the change will be > >relatively slow. Even after Six months at Zero Gee, Shannon Lucid was > >able to walk out of the shuttle after it landed (much to the dismay of > >NASA doctors to be sure.) and this was an abrupt change, a slow build > >up of "gravity" should be easy to adapt to, especially if a strict > >exercise program is instituted. hell, we always wondered what the crew > >would do with their spare time, now we know. They'll be exercising! > > Risian studies on MIR have shown exercise doesn't seem to help much as far > as G induced heath problems. (And they had their guys exercise 6 hours a > day!) Yes, but that is exercise in micro-gravity. Our crew will have some gravity at every stage of the flight. at the start and end, it will be more earth like; near the middle, it will be just like living on the moon. if we can have permanent colonies on luna, we can do this flight. > >I really think this is the best design we've come up with yet. Aside > >from the cost and the political will issues, none of this technology > >is beyond our capability. We know how to make solar collectors, masers, > >linear accelerators and closed system ecologies. > > > >The question remains, can we build them large enough, precise enough, > >efficient enough and will they last long enough to make it to TC and > >back agin. But then, these are engineering problems, not physics > >problems. > > By "them", I assume you mean the sol maser array? Sort of. I mean, can we build the solar collectors big enough, the maser array precise enough, the lineac efficient enough, and will the closed system ecology last long enough. > > > >In contrast, the only other viable alternatives (from a physics > >standpoint) > >is a fusion-sail hybrid (Kelly's fuel-sail) an anti-matter rocket, and > >the argosy concept. The fuel sail and the anti-matter rocket both > >require technology that we do not yet posses, and may have trouble with > >by 2050 or even 2100. The argosy concept would take centuries to > >get to target star. > > > >The MARS remains the Fastest, lightest, and easiest (relatively > >speaking) > >ship to build. > > Hey! You forgot my Explorer class with laser launched fuel canisters for > boost phase! ;) No I didn't, MARS is both faster and lighter. we won't even talk about easier. > > Also you skiped over the technical problem of building and operating the > return launcher array. Also I cringe when physisists come up with ideas > that have clean physics, but very dirty engineering, that they don't want > to worry about. > > ;) > you mean like the explorer with laser launched fuel canisters? ;) > On the other hand if MARS could be made to work, it would have big speed > advantages over the others we've come up with. Thou I wounder about its > range limits. This is one of the problems that's worried Tim. Tim fears that the beam will spread out too much. I think that the beam can be focused into a nearly paralell stream of photons. thus there will be no spreading and diffusion. _IF_ this can be achieved, then range won't be a problem at all. The ship will be able to travel to any star within a good 100 light years on a 3-4 light year pulse of maser energy. Since most of a 100 light-year trip will be spent at insanly high fractions of C, I expect the one-way trip time to be on the order of ten years for the crew. of course a return mission would arrive a good 250 years after departure. Kevin From owner-starship-design Mon Oct 21 08:22 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1752" "Mon" "21" "October" "1996" "09:50:38" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "45" "Re: starship-design: Stellar drive?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA04726 for starship-design-outgoing; Mon, 21 Oct 1996 08:22:32 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA04672 for ; Mon, 21 Oct 1996 08:22:27 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA14787; Mon, 21 Oct 96 09:54:42 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI014475; Mon Oct 21 09:51:42 1996 Received: by most (4.1/SMI-4.1) id AA07226; Mon, 21 Oct 96 09:51:21 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma007217; Mon Oct 21 09:50:39 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA00825; Mon, 21 Oct 96 09:50:36 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1751 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Stellar drive? Date: Mon, 21 Oct 1996 09:50:38 -0500 At 4:27 PM 10/21/96, Timothy van der Linden wrote: >L. Parker wrote: > >>Well, I don't suppose it would be fair if I didn't at least offer an idea >>for a solution. I haven't ever heard of a Faraday cage, and I am not sure >>if it works or how strong of a field it would have to generate in order to >>work, but how about if your second field was the shield also? Shaped kind >>of like this: >> \ >> O | >> / >> >>Just a thought... > >A Faraday cage is a passive thing, it does not generate a field, it converts >the EM-radiation into an electrical current. >It is not a complicated thing, it is merely a wiremesh in the form of a cage >(round, square) it's shape does not matter much, as long as it is closed. >The general theory is that as soon as a difference in fieldstrength is >present between two points of the cage, the electric current will resolve that. >The size of the mesh is important, the smaller the mesh size, the better it >protects against high frequencies. > >By the way, why do we need alternating magnetic fields, or are constant >magnetic fields possible too? > >Timothy Since the magnetic drive system described on that web page uses timed mag pulses from electromagnets. It would seem to be stuck with alternating magnetic fields. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Mon Oct 21 08:22 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6948" "Mon" "21" "October" "1996" "09:48:02" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "163" "Re: starship-design: Re: Solar sail breaking" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA04831 for starship-design-outgoing; Mon, 21 Oct 1996 08:22:48 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA04759 for ; Mon, 21 Oct 1996 08:22:36 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA14430; Mon, 21 Oct 96 09:50:42 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI014336; Mon Oct 21 09:48:55 1996 Received: by most (4.1/SMI-4.1) id AA07152; Mon, 21 Oct 96 09:48:43 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma007148; Mon Oct 21 09:48:02 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA00383; Mon, 21 Oct 96 09:48:00 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 6947 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: "Kevin \"Tex\" Houston" Cc: Starship design group , Nick Tosh <101765.2200@compuserve.com> Subject: Re: starship-design: Re: Solar sail breaking Date: Mon, 21 Oct 1996 09:48:02 -0500 At 12:48 AM 10/21/96, Kevin \"Tex\" Houston wrote: >Nick Tosh wrote: >> >> Hello everybody. >> >> From what I've gathered from reading past mailings, stopping a starship >> powered by a Sol based particle/EM rad beam is a major problem. > >Rex has analysed this problem and a solution >has been found. While Rex claims it's not very efficient, he does >prove that it is theoretically sound, and violates no physical laws. > >The idea is my old Microwave Augmented Rocket System (MARS). A ship >departs earth with tanks full of Reaction Mass (RM), and accelerates >away from earth using a microwave sail. > >At the turn-around point, (not necessarily the halfway point), the >ship converts the energy from the microwaves into electricity, and >uses that to accelerate the RM to a hefty fraction of C. > >This has been shown to yeild more momentum from the "engine", than the >ship would absorb from the sail. > >Mass ratios and exhaust velocities, depend heavily upon conversion >ratios >(converting recieved microwave energy to kinetic energy in the exhaust) >Here is what Rex had to say on this subject. > >--------begin included text------------------------------- >The effects of reduced conversion efficiency (eta less >than 1) on required exhaust velocity, final sail furl and, most >importantly, required mass ratio are given in the table below: > > eta exhaust velocity final sail furl mass ratio > 1.0 0.883 0.160 9.41 > 0.9 0.849 0.105 15.44 > 0.8 0.809 0.060 29.05 > 0.7 0.760 0.029 67.57 > >Producing high efficiency of conversion from received power to >exhaust power may be as challenging (and as crucial to the >success of the concept) as constructing the emitter or the sail. >----------end included text------------------------------- > >So even a fairly high efficiency of .7 means a mass ratio of 68. >This is not too bad, considering some of the other mass ratios I've >seen bandied about. (114 for really good anti matter ship) What are the cruise speeds and flight times that you can get to with this? >Now the problem here is that current linear accelerators are not >very efficient, according to Rex. He states that at best, they are >only about 1% effiecient. > >In a letter I sent to Tim, I said that I doubted current lineac >efficiencies could be used to model practical maximums. > <<>> > >Another problem with this design has been pointed out by Kelly. >I've said that an advantage with this system is that while in flight >we done need any spinning sections. Kelly's point is that this would >have an adverse effect on the crew. > >Because the power beam from earth is constant (to minimize hassle), >and the ship is going to approach light-speed (.9331 of C) then >something has to give. That something is the precieved acceleration >felt by the crew. This will fall to ~1/7 earth normal near the >turn-around point. As the ship begins to decelerate, the "gravity" >will again climb toward earth normal. > >Kelly fears that extended time at less than 1 Gee will have an adverse >effect on the crew. I disagree with this because the change will be >relatively slow. Even after Six months at Zero Gee, Shannon Lucid was >able to walk out of the shuttle after it landed (much to the dismay of >NASA doctors to be sure.) and this was an abrupt change, a slow build >up of "gravity" should be easy to adapt to, especially if a strict >exercise program is instituted. hell, we always wondered what the crew >would do with their spare time, now we know. They'll be exercising! Risian studies on MIR have shown exercise doesn't seem to help much as far as G induced heath problems. (And they had their guys exercise 6 hours a day!) >While it is true that we will need a spinning section while we are in >the target system, we should not need one during the flight. > >So again, I propose the following ship configuration: > >Consider the in-flight section to be like a soda can, and the habitat >section to be like a larger soup can. While accelerating toward TC, >the crew resides in the soda can, at the turn-around point, the soda >can is extracted from the soup can, turned around, and put back in. >Upon reaching TC, the crew moves into the soup can, which is spun up >to provide the required gravity. All of the exploration equipment >is stored in the soup can. The soda can is now free to be rehabed, >and the soup can acts like a dry dock. When the time comes to leave, >the soda can is what returns. the soup can stays behind as a base, >and if for some strange reason, we decide to leave a permanent force >behind, then we have a place for them to live. if not, then everyone >gets back into soda can and heads for earth. The return Module uses >a microwave Sail to accelerate away from TC, and uses Earth's Masers >to decelerate. > >I really think this is the best design we've come up with yet. Aside >from the cost and the political will issues, none of this technology >is beyond our capability. We know how to make solar collectors, masers, >linear accelerators and closed system ecologies. > >The question remains, can we build them large enough, precise enough, >efficient enough and will they last long enough to make it to TC and >back agin. But then, these are engineering problems, not physics >problems. By "them", I assume you mean the sol maser array? >In contrast, the only other viable alternatives (from a physics >standpoint) >is a fusion-sail hybrid (Kelly's fuel-sail) an anti-matter rocket, and >the argosy concept. The fuel sail and the anti-matter rocket both >require technology that we do not yet posses, and may have trouble with >by 2050 or even 2100. The argosy concept would take centuries to >get to target star. > >The MARS remains the Fastest, lightest, and easiest (relatively >speaking) >ship to build. > >Sincerly, > >-- >Kevin "Tex" Houston http://umn.edu/~hous0042/index.html Hey! You forgot my Explorer class with laser launched fuel canisters for boost phase! ;) Also you skiped over the technical problem of building and operating the return launcher array. Also I cringe when physisists come up with ideas that have clean physics, but very dirty engineering, that they don't want to worry about. ;) On the other hand if MARS could be made to work, it would have big speed advantages over the others we've come up with. Thou I wounder about its range limits. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Mon Oct 21 08:26 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2222" "Mon" "21" "October" "1996" "09:37:24" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "52" "starship-design: LIT site 2" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA06214 for starship-design-outgoing; Mon, 21 Oct 1996 08:26:45 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA06173 for ; Mon, 21 Oct 1996 08:26:37 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA13851; Mon, 21 Oct 96 09:40:39 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI013760; Mon Oct 21 09:38:16 1996 Received: by most (4.1/SMI-4.1) id AA06884; Mon, 21 Oct 96 09:38:08 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma006876; Mon Oct 21 09:37:25 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA28878; Mon, 21 Oct 96 09:37:22 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 2221 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: "Kevin \"Tex\" Houston" Cc: Starship design group , Nick Tosh <101765.2200@compuserve.com> Subject: starship-design: LIT site 2 Date: Mon, 21 Oct 1996 09:37:24 -0500 As most of you know. I've been working up a lot of changes for the LIT site and uploading them to Daves Workstation for integration and uploading to SunSITE. Unfortunatly. Unfortunatly Daves been to swamped to do more of the integration, and some parts of the check out can only be done by him, not by an outsider signing in to his workstation. (Also frankly I worry his company will get anoyed with him.) Anyway I was thinking of starting some stuff on a further upgrades (with frames, cleaner Maps, odds and ends), and don't want to be interfearing with what Dave does on his system. (To many integrators trash the file config.) So I've taken Kevin up on his offer to host it on his URLY-Bird site. http://www.urly-bird.com/LIT/ With luck we should have LIT V3 (?) up by spring, and ready for upload to SunSite (asuming its still there). So far I've only uploaded some parts of the stuff I uploaded to Daves system. but it is integrating a bit easier (give or take) the maps worked first time, but were touchier about capitalization. So, what suggestions do people have for the '97 version of the site? What else would you like on it. Hopefully the restructured format of the version curently on Daves office system is exceptable? Ben? Do you still have the Java versions of the conputer center programs? (delta-v, mass ratio, spec implus, and other math goodies.) I know I was worried about compatibility problems with the bulk of the people with pre Java browsers, but by next spring that shouldn't be as much of a problem. Dave. Any thoughs on this? I know SunSite reconfigured, so your PERL versions of the Computer center stuff woun't work. Would Java versions be more supportable? Would certain persons working on MARS and Argosey ship designs get their stuff written up? ;) Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Mon Oct 21 08:37 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1713" "Mon" "21" "October" "1996" "10:34:35" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "54" "Re: starship-design: Re: LIT site 2" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA09728 for starship-design-outgoing; Mon, 21 Oct 1996 08:37:14 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA09698 for ; Mon, 21 Oct 1996 08:37:11 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA18147; Mon, 21 Oct 96 10:36:59 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI018013; Mon Oct 21 10:35:33 1996 Received: by most (4.1/SMI-4.1) id AA08513; Mon, 21 Oct 96 10:35:29 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma008499; Mon Oct 21 10:34:36 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA09890; Mon, 21 Oct 96 10:34:33 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1712 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: Kevin C Houston Cc: Starship design group , Nick Tosh <101765.2200@compuserve.com> Subject: Re: starship-design: Re: LIT site 2 Date: Mon, 21 Oct 1996 10:34:35 -0500 At 9:55 AM 10/21/96, Kevin C Houston wrote: >On Mon, 21 Oct 1996, Kelly Starks x7066 MS 10-39 wrote about LIT2: > > > >> Would certain persons working on MARS and Argosey ship designs get their >> stuff written up? ;) > >EEEP! Ooops, sorry about that. I'll get on it right away. Yes their are certain other reasons to move as version of LIT into your account on your system. ;) > >If anyone wants access to the URLy-bird site, Just E-mail me for the >username/password. since I can't offer eneryone a different password, >I must know who's got access. so please, if I give you the password, >don't give it to anyone else, make them come through me. If you don't >think you'll be doing that much in the site, then please don't ask for >the password. Lets all remember this is Kevins busness site. I>E. there are customers in there with us. SO BE CAREFUL! >Also, I've had a few questions about listserv. Since Steve's doing >such a good job with the darkwing listsever, I wouldn't dream of >messing that up. so my answer is no; no listserv out of urly-bird. > >Later > >Kevin As to list server, were still trying to come up with a good way to upload our comments to the newsletter archive. Currently I'm doing it manually. Which impacts timelyness, and seems inefficent. Ideas? Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Mon Oct 21 08:59 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7362" "Mon" "21" "October" "1996" "10:55:11" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "175" "Re: starship-design: Re: Solar sail breaking" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA18415 for starship-design-outgoing; Mon, 21 Oct 1996 08:59:18 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA18385 for ; Mon, 21 Oct 1996 08:59:08 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA19785; Mon, 21 Oct 96 10:58:08 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI019662; Mon Oct 21 10:56:47 1996 Received: by most (4.1/SMI-4.1) id AA09157; Mon, 21 Oct 96 10:56:45 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma009116; Mon Oct 21 10:55:13 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA13199; Mon, 21 Oct 96 10:55:09 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 7361 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: Kevin C Houston Cc: Starship design group , Nick Tosh <101765.2200@compuserve.com> Subject: Re: starship-design: Re: Solar sail breaking Date: Mon, 21 Oct 1996 10:55:11 -0500 At 10:12 AM 10/21/96, Kevin C Houston wrote: >On Mon, 21 Oct 1996, Kelly Starks x7066 MS 10-39 wrote: > >> At 12:48 AM 10/21/96, Kevin \"Tex\" Houston wrote: >> > >> >The idea is my old Microwave Augmented Rocket System (MARS). A ship >> >departs earth with tanks full of Reaction Mass (RM), and accelerates >> >away from earth using a microwave sail. >> > >> >At the turn-around point, (not necessarily the halfway point), the >> >ship converts the energy from the microwaves into electricity, and >> >uses that to accelerate the RM to a hefty fraction of C. >> > >> >Here is what Rex had to say on this subject. >> > >> >--------begin included text------------------------------- >> >The effects of reduced conversion efficiency (eta less >> >than 1) on required exhaust velocity, final sail furl and, most >> >importantly, required mass ratio are given in the table below: >> > >> > eta exhaust velocity final sail furl mass ratio >> > 1.0 0.883 0.160 9.41 >> > 0.9 0.849 0.105 15.44 >> > 0.8 0.809 0.060 29.05 >> > 0.7 0.760 0.029 67.57 >> > >> >Producing high efficiency of conversion from received power to >> >exhaust power may be as challenging (and as crucial to the >> >success of the concept) as constructing the emitter or the sail. >> >----------end included text------------------------------- >> > >> >So even a fairly high efficiency of .7 means a mass ratio of 68. >> >This is not too bad, considering some of the other mass ratios I've >> >seen bandied about. (114 for really good anti matter ship) >> >> What are the cruise speeds and flight times that you can get to with this? > > >There is no cruise per se. The ship is a constant thrust mission, >but the thrust steadily decreases throughout the mission. then builds >up again. > >top speed is .93 C >flight time is 8 years for the crew, and 15 years for earth. Pretty good for a Tau C. flight. >> Kevin: >> >Another problem with this design has been pointed out by Kelly. >> >I've said that an advantage with this system is that while in flight >> >we done need any spinning sections. Kelly's point is that this would >> >have an adverse effect on the crew. >> > >> >Because the power beam from earth is constant (to minimize hassle), >> >and the ship is going to approach light-speed (.9331 of C) then >> >something has to give. That something is the precieved acceleration >> >felt by the crew. This will fall to ~1/7 earth normal near the >> >turn-around point. As the ship begins to decelerate, the "gravity" >> >will again climb toward earth normal. >> > >> >Kelly fears that extended time at less than 1 Gee will have an adverse >> >effect on the crew. I disagree with this because the change will be >> >relatively slow. Even after Six months at Zero Gee, Shannon Lucid was >> >able to walk out of the shuttle after it landed (much to the dismay of >> >NASA doctors to be sure.) and this was an abrupt change, a slow build >> >up of "gravity" should be easy to adapt to, especially if a strict >> >exercise program is instituted. hell, we always wondered what the crew >> >would do with their spare time, now we know. They'll be exercising! >> >> Risian studies on MIR have shown exercise doesn't seem to help much as far >> as G induced heath problems. (And they had their guys exercise 6 hours a >> day!) > >Yes, but that is exercise in micro-gravity. Our crew will have some >gravity at every stage of the flight. at the start and end, it will >be more earth like; near the middle, it will be just like living on >the moon. if we can have permanent colonies on luna, we can do this >flight. Actualy I doubt well be able to colonise the moon unless we include some artificial G in the bases. L5 colonies anyone? >> >I really think this is the best design we've come up with yet. Aside >> >from the cost and the political will issues, none of this technology >> >is beyond our capability. We know how to make solar collectors, masers, >> >linear accelerators and closed system ecologies. >> > >> >The question remains, can we build them large enough, precise enough, >> >efficient enough and will they last long enough to make it to TC and >> >back agin. But then, these are engineering problems, not physics >> >problems. >> >> By "them", I assume you mean the sol maser array? > >Sort of. I mean, can we build the solar collectors big enough, the >maser array precise enough, the lineac efficient enough, and will >the closed system ecology last long enough. ?! Oh, is that all. ;) >> >In contrast, the only other viable alternatives (from a physics >> >standpoint) >> >is a fusion-sail hybrid (Kelly's fuel-sail) an anti-matter rocket, and >> >the argosy concept. The fuel sail and the anti-matter rocket both >> >require technology that we do not yet posses, and may have trouble with >> >by 2050 or even 2100. The argosy concept would take centuries to >> >get to target star. >> > >> >The MARS remains the Fastest, lightest, and easiest (relatively >> >speaking) >> >ship to build. >> >> Hey! You forgot my Explorer class with laser launched fuel canisters for >> boost phase! ;) > >No I didn't, MARS is both faster and lighter. we won't even talk about >easier. True, but Explorer is a "viable alternatives (from a physics standpoint)". >> Also you skiped over the technical problem of building and operating the >> return launcher array. Also I cringe when physisists come up with ideas >> that have clean physics, but very dirty engineering, that they don't want >> to worry about. >> >> ;) >> > >you mean like the explorer with laser launched fuel canisters? ;) Well I'll admit that had certain... complexity issues. ;) >> On the other hand if MARS could be made to work, it would have big speed >> advantages over the others we've come up with. Thou I wounder about its >> range limits. > >This is one of the problems that's worried Tim. Tim fears that the >beam will spread out too much. I think that the beam can be focused >into a nearly paralell stream of photons. thus there will be no >spreading and diffusion. _IF_ this can be achieved, then range won't >be a problem at all. The ship will be able to travel to any star >within a good 100 light years on a 3-4 light year pulse of maser >energy. Since most of a 100 light-year trip will be spent at insanly >high fractions of C, I expect the one-way trip time to be on the order >of ten years for the crew. of course a return mission would arrive >a good 250 years after departure. > >Kevin As a practical measure it wouldn't make any sence to launch missions that would approach, much less exceed, a century. Not to mention the the crew would have to assume their would be no maser array in operation at sol by the time the return. Such long range flights would have to wait until better (much better) physics. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Mon Oct 21 10:26 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1231" "Mon" "21" "October" "1996" "19:26:04" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "28" "starship-design: Re: Solar sail breaking " "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id KAA07563 for starship-design-outgoing; Mon, 21 Oct 1996 10:26:18 -0700 (PDT) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id KAA07530 for ; Mon, 21 Oct 1996 10:26:12 -0700 (PDT) Received: from hgl1-9.worldaccess.nl by driene.student.utwente.nl with SMTP id AA13946 (5.67b/IDA-1.5 for ); Mon, 21 Oct 1996 19:26:01 +0200 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610211726.AA13946@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1230 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Solar sail breaking Date: Mon, 21 Oct 1996 19:26:04 +0100 Hi Nick, >(The photons is reflected, so its change in momentum is twice the magnitude >of its initial Doppler shifted momentum. I think that the reflected photon >is of the same -shifted- frequency of the incident photon, since otherwise >the solar sail would have to absorb more energy than it radiated, and this >surely cannot be a theoretical requirement; The sail does radiate more energy than it receives. How else are you going to stop the starship and loose kinetic energy. >I need some help on the following point. Does time dilation result in the >high velocity starship intercepting more photons per unit time than an >observer in orbit around the star sees the star emit in the ship's >direction? >Does relativity really increase both the impulse gained from >each photon AND the photon flux (in the ship's frame)? I don't know enough >to answer this, and I'm too tired to think about it now. If the aswer to >this is yes, than I think some serious modelling of the sail brake should >be done immediately. Please could someone answer this for me as soon as >poss. No, either count the amount of photons, or use their frequency. Don't use both particle and wave mechanics. (Rex, please tell me I'm right.) Timothy From owner-starship-design Mon Oct 21 10:26 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3981" "Mon" "21" "October" "1996" "19:25:59" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "78" "starship-design: Re: Stellar Drive" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id KAA07542 for starship-design-outgoing; Mon, 21 Oct 1996 10:26:14 -0700 (PDT) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id KAA07519 for ; Mon, 21 Oct 1996 10:26:09 -0700 (PDT) Received: from hgl1-9.worldaccess.nl by driene.student.utwente.nl with SMTP id AA13941 (5.67b/IDA-1.5 for ); Mon, 21 Oct 1996 19:25:55 +0200 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610211725.AA13941@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 3980 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Stellar Drive Date: Mon, 21 Oct 1996 19:25:59 +0100 >Interesting idea. Is the physics really OK on this one? It sounds dodgy. I >don't follow the author's attempt to keep Newton's third. What if there >were no charged matter in the direction of the escaping fields? If there >were charged matter, would it not make a difference if it was mainly >negative or positive? The magnetic forces would be in opposite directions >for opposite charges. If there were no charged matter moving relative to >the electromagnets, there would again be no possibility of future magnetic >forces making up lost momentum. Does the concept depend on the statistical >distribution of charge and velocity throughout the universe surrounding the >magic drive? Surely the principle of reaction is not statistical in the >sense thermodynamics is. I have a few other points. Timothy wrote: > >>Magnetic fields is just EM-radiation, usually magnetic fields are very low >>frequency radiation, in some cases almost non-alternating. In any case >>photons are exchanged. While stating this, I should have mentioned that non-alternating/changing magnetic fields are not EM-radiation. In this reactionless drive one could make the switching times neglectable to the on-time, which I didn't do. I believe the author of the article did point to this difference. >How would you make a laser pull? Lasers, indeed all real photons, only >push. The force on the target would be cancelled by the reaction to the >laser emission in the emitter, and the system would experince no net force. >With pulling virtual photons, the idea seems to imply an odd free lunch - >the action and reaction are in the same direction. But we still pay for >it... Don't count on free lunches, even virtual photons have to get their momentum from somewhere too. >I think Kevin made a good point about the second electromagnet's field >interacting with the first electromagnet by inducung a current in it. I >don't think that shielding it with a superconductor would help - a current >would be induced in the superconductor, and you would still have your >unwanted reaction force. It would be like a bar magnet hovering over the >eddy currents it produces in a superconductor. There indeed will be a reaction force, but you could make it neglectable by momentarily increasing the resistance of magnet 1. That would prevent the formation of an induced magnetic field. >My final point is that if the system doesn't violate Newton's Third Law, >what's the point of it? Its not really a 'stellar drive' (how did >reactionless drives get that name?) at all. I assume the point of a >reactionless drive is to save a starship from using up its energy on >reaction mass - one would prefer that it convert all its stored energy into >KE for itself. But if the magnetic fields created eventually do accelerate >a distant 'reaction mass', no energy has been saved. So is the concept >really helpful for us? No, like I said, you could just as well use a laser beam to propell yourself. However the concept on itself is interesting. It would probably be possible to do the same with electric fields: - + ======= + - Where -+ are separated charges and ===== is the ship (or plastic rod). Since the positive charges are closer to each other than the negative charges, the net result is both sides reject each other a little. By separating and rejoining the charges you would have a similar effect as switching on and off the magnets. >Just out of interest, is there any way of focussing virtual photons to >concentrate a magnetic field in one direction? I doubt it's possible >without making the photons real first. I suppose that if you have two charges (or charged plates), there will be an increased amount of virtual photons between them. I don't know however, what the difference is between an "attracting" or "pushing" virtual photon. (It may have to do with the fact that a virtual photon has 3 degrees of freedom in contrast to the real photon which has only 2 polarisations.) Timothy From owner-starship-design Wed Oct 23 22:23 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7302" "Thu" "24" "October" "1996" "01:22:56" "-0400" "DotarSojat@aol.com" "DotarSojat@aol.com" nil "158" "starship-design: Required microwave-antenna size. 100-light-year trip." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id WAA19820 for starship-design-outgoing; Wed, 23 Oct 1996 22:23:28 -0700 (PDT) Received: from emout19.mail.aol.com (emout19.mx.aol.com [198.81.11.45]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id WAA19809 for ; Wed, 23 Oct 1996 22:23:24 -0700 (PDT) Received: by emout19.mail.aol.com (8.6.12/8.6.12) id BAA22789 for starship-design@lists.uoregon.edu; Thu, 24 Oct 1996 01:22:56 -0400 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961024012254_1946471101@emout19.mail.aol.com> Precedence: bulk Reply-To: DotarSojat@aol.com Content-Type: text Content-Length: 7301 From: DotarSojat@aol.com Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Required microwave-antenna size. 100-light-year trip. Date: Thu, 24 Oct 1996 01:22:56 -0400 Hi all At 01:43 EDT on 10/21/96, Kevin wrote: >I really think this is the best design we've come up with yet. >Aside from the cost and political will issues, none of this >technology is beyond our capability. We know how to make solar >collectors, masers, linear accelerators and closed system >ecologies. > >The question remains, can we build them large enough, precise >enough, efficient enough and will they last long enough to make >it to TC and back agin. But then, these are engineering prob- >lems, not physics problems. I think Kevin's note from which the above quote was taken is a very good wrap-up of the beam-driven-sail concept, except that the calculated results that he draws from my 9/20 note "Deceler- ation of sail pushed by constant-power beam" were qualified by the condition, "ignoring inverse-square effects." In my 9/11 note, I wrote: "(Note: This exercise may turn out to be purely academic because the inverse-square effects...would be much larger [than the Doppler-shift effects].)" Kevin acknowledged this issue when he wrote, at 11:13 EDT on 10/21: >This is one of the problems that's worried Tim. Tim fears that >the beam will spread out too much. I think that the beam can be >focused into a nearly paralell stream of photons. thus there >will be no spreading and diffusion. _IF_ this can be achieved, >then range won't be a problem at all. The ship will be able to >travel to any star within a good 100 light years on a 3-4 light >year pulse of maser energy. Since most of a 100 light-year trip >will be spent at insanly high fractions of C, I expect the one- >way trip time to be on the order of ten years for the crew. of >course a return mission would arrive a good 250 years after >departure. The above quotes indicate that there are some uncertainties that need to be cleared away with calculations of (1) numbers regard- ing antenna-size requirements to avoid too much beam attenuation due to inverse-square effects, and (2) numbers regarding a 100-lt-yr trip. 1. ANTENNA SIZE REQUIREMENT (A tutorial; read at your own risk.) In the "far field" [range > De^2/(2.44 lambda), to be shown below] of the emitting aperture, focusing to produce a convergent beam (or even "a nearly paralell stream of photons") is not poss- ible, and Fraunhofer diffraction (linear divergence of beam width, or inverse-square dependence of power per unit area, with distance) applies. A diffraction-limited beam ("perfect" antenna shape) contains about 84 percent of its power within the main lobe that has an angular radius of 1.22 lambda/De (where lambda is the wavelength of the emitted radiation and De is the diameter of the emitting aperture). In the "near field," Fraunhofer-diffraction considerations are not available to define the scaling of beam-cross-section ("spot") size with distance. But focusing to produce a conver- gent beam is possible, and we can use simple geometrical-optics considerations to determine the focused-spot size. For a reflecting beam-forming "mirror" (antenna) with a focal length, f, the distance from the mirror to the image spot, di, is related to the distance from the mirror to the object, do, by the relation-- (1/di) + (1/do) = (1/f) , and the magnification, i.e., the ratio of the image size to the object size, is given simply by the ratio, di/do. In our case, the distance from the mirror to the image spot (on the sail) is many, many focal lengths of the mirror, so do does not need to be changed much from f to compensate for the change in di as the sail moves away from the emitter. Therefore the focused image spot size in effect increases directly with di (for constant object size), resulting in an inverse-square dependence of power per unit area again. The range boundary between the "near" and "far" fields can be defined as the distance at which the focused image spot size is equal to the size of the beam-forming aperture, and at that range the spot size is that given by Fraunhofer diffraction (with a factor of 2 to go from radius to diameter), so-- spot diameter = De = range * 2 * 1.22 * lambda/De , or, solving for the range that gives the boundary between the near and far fields, range = De^2/(2.44 lambda) . Q.E.D. If the image spot size at the boundary is that given by Fraun- hofer diffraction, and the spot size has the same dependence on distance in the near field as the Fraunhofer spot has in the far field, then we can use the Fraunhofer angular width to determine the spot size in the near field. (What we can't do in the near field is take the same shape of the power distribution within the spot. The power distribution within the spot is governed by "Fresnel" diffraction, which we'll assume gives a gross distrib- ution not enough different to bother us here.) If we set the Fraunhofer-diffraction angular width equal to the angle subtended by the sail diameter (Ds) at the range R, we can get an expression for the diameter of the emitting antenna (De) that is required to put "84 percent" of the emitted power within the area of the sail: De = 2.44 * lambda * R/Ds . For microwaves with lambda = 1 cm and a sail diameter of 100 km, say, the required diameter of the emitting antenna grows 2.31 million km for each light-year of distance to the sail, to keep the main lobe just within the sail diameter. This is for an antenna whose figure (shape) is correct to a fraction of a wave- length. For an emitting-antenna diameter of 2.31 million km (and wave- length of 1 cm) for a 1-lt-yr distance to the sail, the boundary between near and far fields is at a range of about 23 thousand lt-yr, far enough away to say we're operating in the near field. [Note: at 1 lt-yr distance, the spot size is (1 lt-yr/23,000 lt-yr) * 2.31 x 10^6 km = 100 km, the diameter of the sail, as desired.] Are we prepared to build an expanding antenna this large? It looks as if the M(aser)ARS should be a L(aser)ARS. For any wave- length, however, figure control is going to remain a headache. 2. DATA FOR 100-LIGHT-YEAR TRIP (in spite of the above) A run with the program SAILTRIP (appended to my 9/20 note) with DSTAR = 100 lt-yr gives the following data for the one-way trip: Proper (ship) time = 23.8473 yr Apparent (Earth) time = 104.2934 yr Total Earth time for emission = 4.2934 yr Peak proper velocity = 7.2603 lt-yr/yr Peak apparent velocity = 0.9906 lt-yr/yr Minimum acceleration (at turnover) = 0.0685 g Exhaust velocity for deceleration = 0.89346 lt-yr/yr Mass ratio for deceleration (eta = 1.0) = 33.62 The trip time for the crew is not as short as Kevin estimated ("ten years") because the acceleration is so low for most of the trip. His estimates for emission time ("3-4 ... year"), Earth time for round trip ("a good 250 years") and speed ("insanly high fractions of C") are pretty good, however. Rex (Rex Finke) P.S. To Timothy: You're right in advising Nick not to use aspects of both particle and wave mechanics at the same time to define the Doppler effects. (And welcome back, Nick; even though the Group became aware of me late, I have continuous copies of the LIT Engineering Newsletter from its inception through about April, 1995, to make me aware of previous member contributions.) From owner-starship-design Wed Oct 23 22:46 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1960" "Thu" "24" "October" "1996" "00:50:58" "-0500" "Kevin Houston" "hous0042@maroon.tc.umn.edu" nil "52" "starship-design: Focusing on the problem (or focusing IS the problem)" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id WAA24136 for starship-design-outgoing; Wed, 23 Oct 1996 22:46:24 -0700 (PDT) Received: from mhub0.tc.umn.edu (mhub0.tc.umn.edu [128.101.131.50]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id WAA24087 for ; Wed, 23 Oct 1996 22:46:22 -0700 (PDT) Received: from maroon.tc.umn.edu by mhub0.tc.umn.edu; Thu, 24 Oct 96 00:46:22 -0500 Received: from pub-3-c-36.dialup.umn.edu by maroon.tc.umn.edu; Thu, 24 Oct 96 00:46:20 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <326F03C1.7CC5@maroon.tc.umn.edu> Organization: URLy Bird Productions http://www.urly-bird.com/prices.html X-Mailer: Mozilla 3.0 (Win95; U) MIME-Version: 1.0 References: <961024012254_1946471101@emout19.mail.aol.com> Content-Transfer-Encoding: 7bit Precedence: bulk Reply-To: "Kevin \"Tex\" Houston" Content-Type: text/plain; charset=us-ascii Content-Length: 1959 From: "Kevin \"Tex\" Houston" Sender: owner-starship-design To: Starship design group Subject: starship-design: Focusing on the problem (or focusing IS the problem) Date: Thu, 24 Oct 1996 00:50:58 -0500 DotarSojat@aol.com wrote: > 2. DATA FOR 100-LIGHT-YEAR TRIP (in spite of the above) > > A run with the program SAILTRIP (appended to my 9/20 note) with > DSTAR = 100 lt-yr gives the following data for the one-way trip: > > Proper (ship) time = 23.8473 yr > Apparent (Earth) time = 104.2934 yr > Total Earth time for emission = 4.2934 yr > Peak proper velocity = 7.2603 lt-yr/yr > Peak apparent velocity = 0.9906 lt-yr/yr > Minimum acceleration (at turnover) = 0.0685 g > Exhaust velocity for deceleration = 0.89346 lt-yr/yr > Mass ratio for deceleration (eta = 1.0) = 33.62 > > The trip time for the crew is not as short as Kevin estimated > ("ten years") because the acceleration is so low for most of the Hey! I'm nearly within a factor of 2. Not bad for a rough guess 8-p > trip. His estimates for emission time ("3-4 ... year"), Earth > time for round trip ("a good 250 years") and speed ("insanly > high fractions of C") are pretty good, however. > > Rex (Rex Finke) > > P.S. To Timothy: You're right in advising Nick not to use aspects > of both particle and wave mechanics at the same time to define > the Doppler effects. (And welcome back, Nick; even though the > Group became aware of me late, I have continuous copies of the > LIT Engineering Newsletter from its inception through about > April, 1995, to make me aware of previous member contributions.) Okay, Now about focusing, Do you mean to say, that a mirror (forget masers, starships, and everything else for the moment) just a simple mirror cannot be made to focus on a spot 6 lightyears distant? I find this really hard to accept. What is the nature of the interference, or have I mis-understood what you said. I'm going to go back and read your message again. hopefully more of it will make sense this time. -- Kevin "Tex" Houston http://umn.edu/~hous0042/index.html From owner-starship-design Thu Oct 24 06:18 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3815" "Thu" "24" "October" "1996" "08:13:05" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "83" "Re: starship-design: Required microwave-antenna size. 100-light-year trip." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id GAA08036 for starship-design-outgoing; Thu, 24 Oct 1996 06:18:03 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id GAA08023 for ; Thu, 24 Oct 1996 06:17:53 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA21061; Thu, 24 Oct 96 08:16:23 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI020954; Thu Oct 24 08:14:42 1996 Received: by most (4.1/SMI-4.1) id AA03363; Thu, 24 Oct 96 08:14:35 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma003324; Thu Oct 24 08:13:05 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA24832; Thu, 24 Oct 96 08:13:02 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 3814 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: DotarSojat@aol.com Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Required microwave-antenna size. 100-light-year trip. Date: Thu, 24 Oct 1996 08:13:05 -0500 At 1:22 AM 10/24/96, DotarSojat@aol.com (Rex Finke) wrote: -------- >The range boundary between the "near" and "far" fields can be >defined as the distance at which the focused image spot size is >equal to the size of the beam-forming aperture, and at that range >the spot size is that given by Fraunhofer diffraction (with a >factor of 2 to go from radius to diameter), so-- > spot diameter = De = range * 2 * 1.22 * lambda/De ??? Doesn't De = range * 2 * 1.22 * lambda/De Reduce to 1 = range * 2 * 1.22 * lambda >If we set the Fraunhofer-diffraction angular width equal to the >angle subtended by the sail diameter (Ds) at the range R, we can >get an expression for the diameter of the emitting antenna (De) >that is required to put "84 percent" of the emitted power within >the area of the sail: > De = 2.44 * lambda * R/Ds . > >For microwaves with lambda = 1 cm and a sail diameter of 100 km, >say, the required diameter of the emitting antenna grows 2.31 >million km for each light-year of distance to the sail, to keep >the main lobe just within the sail diameter. This is for an >antenna whose figure (shape) is correct to a fraction of a wave- >length. > >For an emitting-antenna diameter of 2.31 million km (and wave- >length of 1 cm) for a 1-lt-yr distance to the sail, the boundary >between near and far fields is at a range of about 23 thousand >lt-yr, far enough away to say we're operating in the near field. >[Note: at 1 lt-yr distance, the spot size is >(1 lt-yr/23,000 lt-yr) * 2.31 x 10^6 km = 100 km, the diameter of >the sail, as desired.] > >Are we prepared to build an expanding antenna this large? It >looks as if the M(aser)ARS should be a L(aser)ARS. For any wave- >length, however, figure control is going to remain a headache. This is much better than I would have guessed. By the way when you say that: "This is for an antenna whose figure (shape) is correct to a fraction of a wave-length." Is this lateral, or for aft drift? I'm of course thinking of a synthetic appiture phased array antena made out of syncronised free floating, solar powered, orbital power platforms. If you assume the platforms are in earths orbit around the sun thats a 306 million kilometer ring around the sun. Thou computing their position accuratly enough to phase lock their output to the desired precision will be a pain! Also you couldn't focus the beam to the ships exact sail size since you couldn't know where exactly the ship is. So you'ld need to focus to a wider beam area (say ten times wider) and give the ship some ara to drift around in. Questions: How much range deviation can you tolerate? Since the beam is being aimed at a ship you can't see in real time. You'ld have to expect it would drift ahead or behind the exact focus spot. How much slack is allowed? What is the lateral deviation of the beam? I.E. whats the power per m^2 in the center vs the edge of the focused spot? The differences would distort the sail and alter the ships course and acceleration. As mentioned above, how precicely can we measure the possition of an object floating in space? Assuming each microwave emmiter platform has laser ranging info to each/some of the others. Can you get the nessisary possitional accuracy? (Within a couple MM?) Note you don't need to control the position that accurately, just know what it is so you can compensate for it. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Thu Oct 24 08:50 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6325" "Thu" "24" "October" "1996" "16:48:43" "+0100" "Zenon Kulpa" "zkulpa@zmit1.ippt.gov.pl" nil "131" "Re: starship-design: Required microwave-antenna size. 100-light-year trip." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA17381 for starship-design-outgoing; Thu, 24 Oct 1996 08:50:34 -0700 (PDT) Received: from zmit1.ippt.gov.pl (zmit1.ippt.gov.pl [148.81.53.40]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA17287 for ; Thu, 24 Oct 1996 08:50:23 -0700 (PDT) Received: by zmit1.ippt.gov.pl (4.1/SMI-4.1) id AA06752; Thu, 24 Oct 96 16:48:43 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <9610241548.AA06752@zmit1.ippt.gov.pl> Precedence: bulk Reply-To: zkulpa@zmit1.ippt.gov.pl (Zenon Kulpa) Content-Type: text Content-Length: 6324 From: zkulpa@zmit1.ippt.gov.pl (Zenon Kulpa) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Cc: zkulpa Subject: Re: starship-design: Required microwave-antenna size. 100-light-year trip. Date: Thu, 24 Oct 96 16:48:43 +0100 > From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) > > At 1:22 AM 10/24/96, DotarSojat@aol.com (Rex Finke) wrote: > -------- > >The range boundary between the "near" and "far" fields can be > >defined as the distance at which the focused image spot size is > >equal to the size of the beam-forming aperture, and at that range > >the spot size is that given by Fraunhofer diffraction (with a > >factor of 2 to go from radius to diameter), so-- > > spot diameter = De = range * 2 * 1.22 * lambda/De > > ??? Doesn't De = range * 2 * 1.22 * lambda/De > Reduce to 1 = range * 2 * 1.22 * lambda > No. It reduces to: De^2 = range * 2 * 1.22 * lambda ;-)) > Questions: > How much range deviation can you tolerate? Since the beam is being aimed > at a ship you can't see in real time. You'ld have to expect it would drift > ahead or behind the exact focus spot. How much slack is allowed? > > What is the lateral deviation of the beam? I.E. whats the power per m^2 in > the center vs the edge of the focused spot? The differences would distort > the sail and alter the ships course and acceleration. > > As mentioned above, how precicely can we measure the possition of an object > floating in space? Assuming each microwave emmiter platform has laser > ranging info to each/some of the others. Can you get the nessisary > possitional accuracy? (Within a couple MM?) Note you don't need to > control the position that accurately, just know what it is so you can > compensate for it. > Let me recall below my deviation tables, buried long ago in the old LIT newsletter archives. Note that the table gives deviation at target due to the change of ORIENTATION of the beaming device, the sensitivity to change of its POSITION is, fortunately, far smaller. Actually the sensitivity factor for position change equals 1 (one) - how much the platform moves sideways, so much does the beam at target (after some years...). However, if the platform moves along the Sun-centered orbit, its velocity is of the order of tens of kilometers a second (see another table below), hence it must compensate for its change of position with appropriate change of orientation, and the latter must be VERY accurate (as the deviation table shows). Moreover, the change of orientation must change very accurately with the distance to the target ship. The latter, I am afraid, is hard to know exactly in real time at long distances (e.g., the acceleration/speed will vary due to many factors, among others the accuracy of aiming the beam [and hence the thrust], the distribution of unknown masses along the way [e.g., invisible gas clouds or stray brown dwarf nearby...]). ================================================================== The beaming platform must orbit the Sun, thus: a) It will move quite fast, depending on the distance from the Sun, e.g: Distance Orbit from Sun Velocity Remarks of [mln km] [km/s] ---------------------------------------------------------------- Mercury 60 50 good place for solar-powered lasers Earth 150 30 near home... Jupiter 800 13 lots of local resources & moons to mine Pluto 6000 5 rather too far... b) So, it must constantly change its aim if it is not going to miss the target by hundreds of kilometers every 10 sec or so... And by how much it must change the aim? I have compiled the table below, where: "Size" is the "principal" dimension of the laser/maser gun component (e.g., the length of the laser "tube", or the diameter of the deflecting mirror, or microvawe antenna dish); "Tilt" is the amount by which one end/edge of the gun component moves relative to the opposite one (in milimeters); "Angle" is the tilt angle (in radians) corresponding to this tilt; "Distance" is the distance to the target (in light years), and the table entries contain the "Sweep" (in kilometers), i.e. approximate distance by which the beam moves sideways at the target distance: We have: Sweep/Distance = Tilt/Size I.e. (for small angles): Sweep = Distance * Angle[radians] Angle = Tilt/Size For simplicity, in the table I have rounded the light year to 10^13 km (instead of more exact 9.4543*10^12 km). Size Tilt Angle | Distance to target [ly] [km] [mm] [rad] | 1 5 10 ----------------------+------------------------------------------------ 0.1 0.1 10^-6 | 10 000 000 50 000 000 100 000 000 km 1 10^-5 | 100 000 000 500 000 000 1 000 000 000 km 10 10^-4 | 1 000 000 000 5 000 000 000 10 000 000 000 km ----------------------+------------------------------------------------ 1 0.1 10^-7 | 1 000 000 5 000 000 10 000 000 km 1 10^-6 | 10 000 000 50 000 000 100 000 000 km 10 10^-5 | 100 000 000 500 000 000 1 000 000 000 km ----------------------+------------------------------------------------ 10 0.1 10^-8 | 100 000 500 000 1 000 000 km 1 10^-7 | 1 000 000 5 000 000 10 000 000 km 10 10^-6 | 10 000 000 50 000 000 100 000 000 km ----------------------+------------------------------------------------ 100 0.1 10^-9 | 10 000 50 000 100 000 km 1 10^-8 | 100 000 500 000 1 000 000 km 10 10^-7 | 1 000 000 5 000 000 10 000 000 km ----------------------------------------------------------------------- [Note: for mirrors you must MULTIPLY the result by 2] I.e., a 100-kilometer diameter microvawe dish tilted by only 1 mm (1/25th of an inch) at the edge, sweeps the beam at 1 ly distance by 100 000 (one HUNDRED thousand) kilometers! (i.e., almost one-third of the Earth-Moon distance) I am afraid that such deflections are easily obtainable by heat distortions of the structure or gravitational perturbation from an asteroid flying some million kilometers away... ================================================================== -- Zenon From owner-starship-design Thu Oct 24 09:28 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7382" "Thu" "24" "October" "1996" "11:24:30" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "164" "Re: starship-design: Required microwave-antenna size. 100-light-year trip." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id JAA05221 for starship-design-outgoing; Thu, 24 Oct 1996 09:28:34 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id JAA05201 for ; Thu, 24 Oct 1996 09:28:26 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA03745; Thu, 24 Oct 96 11:27:44 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI003565; Thu Oct 24 11:25:44 1996 Received: by most (4.1/SMI-4.1) id AA08428; Thu, 24 Oct 96 11:25:41 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma008398; Thu Oct 24 11:24:32 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA23880; Thu, 24 Oct 96 11:24:29 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 7381 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: zkulpa@zmit1.ippt.gov.pl (Zenon Kulpa) Cc: starship-design@lists.uoregon.edu, zkulpa@darkwing.uoregon.edu Subject: Re: starship-design: Required microwave-antenna size. 100-light-year trip. Date: Thu, 24 Oct 1996 11:24:30 -0500 At 4:48 PM 10/24/96, Zenon Kulpa wrote: >> From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) >> >> At 1:22 AM 10/24/96, DotarSojat@aol.com (Rex Finke) wrote: >> -------- >> >The range boundary between the "near" and "far" fields can be >> >defined as the distance at which the focused image spot size is >> >equal to the size of the beam-forming aperture, and at that range >> >the spot size is that given by Fraunhofer diffraction (with a >> >factor of 2 to go from radius to diameter), so-- >> > spot diameter = De = range * 2 * 1.22 * lambda/De >> >> ??? Doesn't De = range * 2 * 1.22 * lambda/De >> Reduce to 1 = range * 2 * 1.22 * lambda >> >No. It reduces to: De^2 = range * 2 * 1.22 * lambda ;-)) AAAAAAAAAHHHHHHHHHHHHHH!!!! I don't beleave I screwed that up!! >> Questions: >> How much range deviation can you tolerate? Since the beam is being aimed >> at a ship you can't see in real time. You'ld have to expect it would drift >> ahead or behind the exact focus spot. How much slack is allowed? >> >> What is the lateral deviation of the beam? I.E. whats the power per m^2 in >> the center vs the edge of the focused spot? The differences would distort >> the sail and alter the ships course and acceleration. >> >> As mentioned above, how precicely can we measure the possition of an object >> floating in space? Assuming each microwave emmiter platform has laser >> ranging info to each/some of the others. Can you get the nessisary >> possitional accuracy? (Within a couple MM?) Note you don't need to >> control the position that accurately, just know what it is so you can >> compensate for it. >> >Let me recall below my deviation tables, buried long ago >in the old LIT newsletter archives. >Note that the table gives deviation at target due to >the change of ORIENTATION of the beaming device, >the sensitivity to change of its POSITION is, fortunately, far smaller. >Actually the sensitivity factor for position change equals 1 (one) - >how much the platform moves sideways, so much does the beam at target >(after some years...). >However, if the platform moves along the Sun-centered orbit, >its velocity is of the order of tens of kilometers a second >(see another table below), hence it must compensate >for its change of position with appropriate change of orientation, >and the latter must be VERY accurate (as the deviation table shows). >Moreover, the change of orientation must change very accurately >with the distance to the target ship. The latter, I am afraid, >is hard to know exactly in real time at long distances >(e.g., the acceleration/speed will vary due to many factors, >among others the accuracy of aiming the beam [and hence the >thrust], the distribution of unknown masses along the way >[e.g., invisible gas clouds or stray brown dwarf nearby...]). > >================================================================== >The beaming platform must orbit the Sun, thus: > >a) It will move quite fast, depending on the distance > from the Sun, e.g: > > Distance > Orbit from Sun Velocity Remarks > of [mln km] [km/s] > ---------------------------------------------------------------- > Mercury 60 50 good place for solar-powered lasers > Earth 150 30 near home... > Jupiter 800 13 lots of local resources & moons to mine > Pluto 6000 5 rather too far... > >b) So, it must constantly change its aim if it is not going > to miss the target by hundreds of kilometers every 10 sec or so... > And by how much it must change the aim? > I have compiled the table below, where: > > "Size" is the "principal" dimension of the laser/maser gun component > (e.g., the length of the laser "tube", or the diameter > of the deflecting mirror, or microvawe antenna dish); > "Tilt" is the amount by which one end/edge of the gun component > moves relative to the opposite one (in milimeters); > "Angle" is the tilt angle (in radians) corresponding to this tilt; > "Distance" is the distance to the target (in light years), > and the table entries contain the "Sweep" (in kilometers), > i.e. approximate distance by which the beam moves sideways > at the target distance: Thank you! Variable names, not letters. You even remembered Units! :) >We have: > > Sweep/Distance = Tilt/Size > >I.e. (for small angles): > > Sweep = Distance * Angle[radians] > Angle = Tilt/Size > >For simplicity, in the table I have rounded the light year >to 10^13 km (instead of more exact 9.4543*10^12 km). > > Size Tilt Angle | Distance to target [ly] > [km] [mm] [rad] | 1 5 10 >----------------------+------------------------------------------------ > 0.1 0.1 10^-6 | 10 000 000 50 000 000 100 000 000 km > 1 10^-5 | 100 000 000 500 000 000 1 000 000 000 km > 10 10^-4 | 1 000 000 000 5 000 000 000 10 000 000 000 km >----------------------+------------------------------------------------ > 1 0.1 10^-7 | 1 000 000 5 000 000 10 000 000 km > 1 10^-6 | 10 000 000 50 000 000 100 000 000 km > 10 10^-5 | 100 000 000 500 000 000 1 000 000 000 km >----------------------+------------------------------------------------ > 10 0.1 10^-8 | 100 000 500 000 1 000 000 km > 1 10^-7 | 1 000 000 5 000 000 10 000 000 km > 10 10^-6 | 10 000 000 50 000 000 100 000 000 km >----------------------+------------------------------------------------ >100 0.1 10^-9 | 10 000 50 000 100 000 km > 1 10^-8 | 100 000 500 000 1 000 000 km > 10 10^-7 | 1 000 000 5 000 000 10 000 000 km >----------------------------------------------------------------------- > [Note: for mirrors you must MULTIPLY the result by 2] > > I.e., a 100-kilometer diameter microvawe dish > tilted by only 1 mm (1/25th of an inch) at the edge, sweeps the beam > at 1 ly distance by 100 000 (one HUNDRED thousand) kilometers! > (i.e., almost one-third of the Earth-Moon distance) > > I am afraid that such deflections are easily obtainable > by heat distortions of the structure or gravitational perturbation > from an asteroid flying some million kilometers away... > >================================================================== > >-- Zenon It does seem targeting sweep and focus will be a problem. Without incredably precise positional info of the platforms, the beam won't be accurate. If the platforms are to close, the beam loses focus. If they are to far apart, they are hard to syncronise and tend to defuse the beam. Hey Kev', Guess thats one advantage of my Fuel/sail or Explorer class designs. You only need to beam to the ship at close range. ;) Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Fri Oct 25 06:34 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4268" "Fri" "25" "October" "1996" "08:30:18" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "111" "starship-design: New 'rebel' planet found" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id GAA14387 for starship-design-outgoing; Fri, 25 Oct 1996 06:34:15 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id GAA14376 for ; Fri, 25 Oct 1996 06:34:11 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA09778; Fri, 25 Oct 96 08:34:05 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI009625; Fri Oct 25 08:31:55 1996 Received: by most (4.1/SMI-4.1) id AA05069; Fri, 25 Oct 96 08:31:51 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma005010; Fri Oct 25 08:30:21 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA04767; Fri, 25 Oct 96 08:30:16 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 4267 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: starship-design@lists.uoregon.edu, MLEN3097@Mercury.GC.PeachNet.EDU, KellySt@aol.com, sdudley@ix.netcom.com, schlegel@rmc1.crocker.com, JohnFrance@aol.com, mark_jensen@cpqm.mail.saic.com, DTaylor648@aol.com, Viper7997@aol.com Subject: starship-design: New 'rebel' planet found Date: Fri, 25 Oct 1996 08:30:18 -0500 New 'rebel' planet found outside solar system It's 'roller-coaster orbit' stuns scientists October 23, 1996 Web posted at: 11:00 p.m. EDT TUCSON, Arizona (AP) -- A new planet that breaks all the rules about how and where planets form has been identified in orbit of a twin star about 70 light years from Earth in a constellation commonly known as the Northern Cross. The new planet has a roller-coaster like orbit that swoops down close to its central star and then swings far out into frigid fringes, following a strange egg-shaped orbit that is unlike that of any other known planet. "We don't understand how it could have formed in such an orbit," said William D. Cochran, head of University of Texas team that discovered the planet at the same time that a group from San Francisco State found it independently. The researchers presented papers on the new planet Wednesday at a national meeting of the American Astronomical Society's planetary division. The new planet is the latest in a series of bodies found in orbit of stars outside the solar system and is part of a quickening effort by astronomers to find distant worlds. Cochran said the planet orbits the smaller of twin stars in the constellation Cygnus, a prominent stellar grouping known as the Northern Cross. The planet's star is called 16 Cygni B and the larger companion star is 16 Cygni A. "Of all the stars you might see in the sky, Cygni B is the most similar to our sun," said Cochran. It has the same mass and temperature as the sun, but the nearby twin star of Cygni B creates an entirely different type of environment. Every 250,000 years, Cygni A and B pass within 65 billion miles of each other, a grazing passage by stellar standards. Cochran said the stars are so close, that the gravitational tug of Cygni A may have pulled the new planet into its wildly eccentric orbit. It is unlikely that life exists on the new planet, said Cochran, because it probably is more like the gaseous planets, such as Jupiter or Saturn, than the rocky planets such as Earth or Mars. The wide-swinging orbit of the planet would also cause extreme fluctuations in temperature, he said. During one part of its 804-day-long year, the planet would pass within 67 million miles of its sun. This would be the planet's summer, said Cochran. Then the planet would swing far out, reaching a point 158 million miles from the star. This would be its winter and it would last more than 500 days, the researcher said. Most planets in the solar system have an almost circular orbit, like that of the Earth, and most theories about how planets form are based on them settling into a circular orbit. The eccentric orbit of the new planet adds a new dimension that astronomers will have to consider in theories about planetary formation, Cochran said. The University of Texas and San Francisco astronomers found the new planet by studying the movement of Cygni B. They discovered that the star tended to change its speed of motion in a way that could only be explained by the presence of an orbiting companion. Cygni A has no such motion, said Cochran, suggesting it has no planet. By some counts, the new planet is the ninth to be found outside the solar system, although some astronomers say there have been up to 11 found. Cochran said the exact number is controversial because not all of the discoveries have been generally accepted as actual planets. And there were skeptics even of the Cochran discovery. "It is a really nice piece of work" said David Black of the Lunar and Planetary Institute in Houston. "But I really question whether this is a planet or a brown dwarf." A brown dwarf is a failed star, an object that never collected enough mass to start stellar burning. Black said it is possible that most of the recently discovered planets are really brown dwarfs. ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Fri Oct 25 08:34 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3058" "Fri" "25" "October" "1996" "10:31:04" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "70" "starship-design: Re: New 'rebel' planet found" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA18116 for starship-design-outgoing; Fri, 25 Oct 1996 08:34:51 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA18087 for ; Fri, 25 Oct 1996 08:34:40 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA17175; Fri, 25 Oct 96 10:34:04 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI017040; Fri Oct 25 10:32:08 1996 Received: by most (4.1/SMI-4.1) id AA08081; Fri, 25 Oct 96 10:32:03 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma008063; Fri Oct 25 10:31:06 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA26122; Fri, 25 Oct 96 10:31:02 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 3057 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: Mark Schlegel Cc: Kelly Starks x7066 MS 10-39 , starship-design@lists.uoregon.edu, MLEN3097@Mercury.GC.PeachNet.EDU, KellySt@aol.com, sdudley@ix.netcom.com, JohnFrance@aol.com, mark_jensen@cpqm.mail.saic.com, DTaylor648@aol.com, Viper7997@aol.com Subject: starship-design: Re: New 'rebel' planet found Date: Fri, 25 Oct 1996 10:31:04 -0500 At 10:10 AM 10/25/96, Mark Schlegel wrote: >On Fri, 25 Oct 1996, Kelly Starks x7066 MS 10-39 wrote: > >> New 'rebel' planet found outside solar system It's 'roller-coaster >>orbit' stuns >> scientists >> >> October 23, 1996 >> Web posted at: 11:00 p.m. EDT >> >> TUCSON, Arizona (AP) -- A new planet that >> breaks all the rules about how and where >> planets form has been identified in orbit of a >> twin star about 70 light years from Earth in a >> constellation commonly known as the >> Northern Cross. >> >> The new planet has a roller-coaster like orbit that swoops down close to >> its central star and then swings far out into frigid fringes, >> following a strange egg-shaped orbit that is unlike that of any other >> known planet. >> "We don't understand how it could have formed in such an orbit," said >> William D. Cochran, head of University of Texas team that discovered >> the planet at the same time that a group from San Francisco State found >> it independently. > >This is a really weird discovery, the best planet formation theory >I think are the disk/planetesimal theories in which a disk of >dust and gas condenses to small bodies that collide and stick to >form planetesimals and then later protoplanets and planets. >The model predicts that the final orbits be relatively circular >because it's difficult for the original disk of dust and gas to have >any radial motion for any length of time since the gas/dust rubs >together and the motion circularizes. You would have to have the >large bodies forming so fast that they could lock in the eccentric >motion or planets form some other way. Odd planet rotations in our >system (like Uranus rotating on it's side at inclination 97 degrees >or whatever) are currently modeled as due to huge 'finishing up' >collisions between the last and largest protoplanets (like >Uranus getting hit obliquely by a Mar's sized object that >resulted in it's final spin being at 97). This eccentric planet >will bother a lot of theorists and will stoke the oddball >astro theories on the internet (go read some Abian or "ludwig >plutonium" on Sci.astro and you'll see what I mean) > >Mark The universe is a violent place. PLanets get blasted around all over the place. Its thought our Moon was the result of a Mars sized planet blasting into the proto earth. I've no idea what could have rolled Uranus over on its side. Turbulance in the disk? This is one of the reasons I never took to seriously the people who were SURE multi-star systems couldn't have planets. We have no idea how other star systems formed, we can't really figure out this one jelled. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Fri Oct 25 11:15 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["836" "Fri" "25" "October" "1996" "13:12:36" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "22" "starship-design: Did Deepflight fly?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id LAA00642 for starship-design-outgoing; Fri, 25 Oct 1996 11:15:01 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id LAA00531 for ; Fri, 25 Oct 1996 11:14:56 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA03080; Fri, 25 Oct 96 13:14:43 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI002966; Fri Oct 25 13:13:07 1996 Received: by most (4.1/SMI-4.1) id AA11585; Fri, 25 Oct 96 13:13:01 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma011575; Fri Oct 25 13:12:38 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA24698; Fri, 25 Oct 96 13:12:34 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 835 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: starship-design@lists.uoregon.edu, Viper7997@aol.com, KellySt@aol.com, sdudley@ix.netcom.com, schlegel@rmc1.crocker.com, JohnFrance@aol.com, mark_jensen@cpqm.mail.saic.com, DTaylor648@aol.com Subject: starship-design: Did Deepflight fly? Date: Fri, 25 Oct 1996 13:12:36 -0500 http://www.deepflight.com/ I was woundering if any heard if the deep Flght submarine started testing yesterday like it was supposed to? The DeepFlight is Graham Hawkes composit and plastic deep diver. Its the size of a small sports car, has a clear plastic nose the pilot lies prone in, handels like a mini aircraft, and is rated for the bottom of the Marianis treanch (7 miles down). (Cheak out the web page.) Kelly Starks ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Fri Oct 25 11:32 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1097" "Fri" "25" "October" "1996" "13:29:50" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "33" "Re: starship-design: Did Deepflight fly?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id LAA11208 for starship-design-outgoing; Fri, 25 Oct 1996 11:32:40 -0700 (PDT) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id LAA11191 for ; Fri, 25 Oct 1996 11:32:36 -0700 (PDT) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA04457; Fri, 25 Oct 96 13:32:14 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI004366; Fri Oct 25 13:30:39 1996 Received: by most (4.1/SMI-4.1) id AA11924; Fri, 25 Oct 96 13:30:36 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma011907; Fri Oct 25 13:29:52 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA27749; Fri, 25 Oct 96 13:29:49 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1096 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Cc: starship-design@lists.uoregon.edu, Viper7997@aol.com, KellySt@aol.com, sdudley@ix.netcom.com, schlegel@rmc1.crocker.com, JohnFrance@aol.com, mark_jensen@cpqm.mail.saic.com, DTaylor648@aol.com Subject: Re: starship-design: Did Deepflight fly? Date: Fri, 25 Oct 1996 13:29:50 -0500 At 1:12 PM 10/25/96, Kelly Starks x7066 MS 10-39 wrote: >http://www.deepflight.com/ > >I was woundering if any heard if the deep Flght submarine started testing >yesterday like it was supposed to? The DeepFlight is Graham Hawkes >composit and plastic deep diver. Its the size of a small sports car, has a >clear plastic nose the pilot lies prone in, handels like a mini aircraft, >and is rated for the bottom of the Marianis treanch (7 miles down). (Cheak >out the web page.) > >Kelly Starks OK, I ansered my own question off the web. The 1000 meter depth prototype did its first test flight/dive yesterday. Pictures at following site. http://www.deepflight.com/events.htm Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Sat Oct 26 17:06 PDT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1617" "Sun" "27" "October" "1996" "02:06:44" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "38" "starship-design: Re: Required microwave-antenna size. 100-light-year trip." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id RAA20171 for starship-design-outgoing; Sat, 26 Oct 1996 17:06:52 -0700 (PDT) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id RAA20134 for ; Sat, 26 Oct 1996 17:06:47 -0700 (PDT) Received: from hgl3-9.worldaccess.nl by driene.student.utwente.nl with SMTP id AA13184 (5.67b/IDA-1.5 for ); Sun, 27 Oct 1996 02:06:44 +0200 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610270006.AA13184@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1616 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Required microwave-antenna size. 100-light-year trip. Date: Sun, 27 Oct 1996 02:06:44 +0100 Zenon wrote: >However, if the platform moves along the Sun-centered orbit, >its velocity is of the order of tens of kilometers a second >(see another table below), hence it must compensate >for its change of position with appropriate change of orientation, >and the latter must be VERY accurate (as the deviation table shows). >================================================================== >The beaming platform must orbit the Sun, thus: > >a) It will move quite fast, depending on the distance > from the Sun, e.g: > > Distance > Orbit from Sun Velocity Remarks > of [mln km] [km/s] > ---------------------------------------------------------------- > Mercury 60 50 good place for solar-powered lasers > Earth 150 30 near home... > Jupiter 800 13 lots of local resources & moons to mine > Pluto 6000 5 rather too far... I'd rather turn things around, not let the emitter follows the ship, but let the ship follows the emitted beam. The beaming station makes a "focussed" (as far as interference allows) an beams it straight forward (in the direction of Tau Ceti). In this case not the velocity of the orbiting station is important, but it's acceleration (to the center of gravity), which is rather low. Low enough for the starship to compensate and change its direction. Also a note to Kelly, the lasers/masers have to be in sync, not having phased lasers will decrease the effectivity immensly due to diffration. To overcome difficulties, building it on a moon would not be a bad idea Timothy From owner-starship-design Sun Oct 27 20:24 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2167" "Sun" "27" "October" "1996" "23:23:40" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "49" "starship-design: Fwd: Re: New 'rebel' planet found" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id UAA16056 for starship-design-outgoing; Sun, 27 Oct 1996 20:24:08 -0800 (PST) Received: from emout09.mail.aol.com (emout09.mx.aol.com [198.81.11.24]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id UAA16041 for ; Sun, 27 Oct 1996 20:24:06 -0800 (PST) Received: by emout09.mail.aol.com (8.6.12/8.6.12) id XAA22450 for starship-design@lists.uoregon.edu; Sun, 27 Oct 1996 23:23:40 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961027232338_133440770@emout09.mail.aol.com> Precedence: bulk Reply-To: KellySt@aol.com Content-Type: text Content-Length: 2166 From: KellySt@aol.com Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Fwd: Re: New 'rebel' planet found Date: Sun, 27 Oct 1996 23:23:40 -0500 --------------------- Forwarded message: Subj: Re: New 'rebel' planet found Date: 96-10-26 16:29:36 EST From: Viper7997 To: kgstar@most.fw.hac.com To: starship-design@lists.uoregon.edu To: MLEN3097@mercury.gc.peachnet.edu To: Kelly St,sdudley@ix.netcom.com To: schlege@rmc1.crocker.com,JohnFrance To: mark_jensen@cpqm.mail.saic.com To: DTaylor648 This, as published on Sky and Telescope's Wep Page (http://www.skypub.com), and can be found on AOL in the Astronomy Club (Keyword: ASTRONOMY)... PLANET IN A MULTIPLE STAR SYSTEM Meanwhile, researchers at McDonald and Lick observatories have independently discovered a planet orbiting the star 16 Cygni B, which is part of a triple-star system about 100 light-years from Earth. The teams have not actually seen the planet itself, but rather the wobbling motion it induces in the star. The teams have been monitoring this star system since the late 1980s, and they combined their data for this joint announcement. No large planets have been detected yet around the other two stars. 16 Cygni B is considered a close match to our Sun in brightness and temperature. The first-ever detection of a planet in a multiple-star system would be unusual enough, but this planet has some interesting quirks of its own. First, it is much less massive than most of the other extrasolar planets found to date, with a mass that could be as little as 1.6 times that of Jupiter. Thus it is probably a true planet rather than a brown dwarf. Also, it circles the star every 2.2 years in a highly eccentric orbit (e = 0.67), which means its distance from the star ranges between 84 and 425 million km, averaging about 250. How a planet can be so big yet in such an eccentric orbit is a puzzling challenge to theorists. Also, there are a few WWW sites about the extrasolar planets: http://cannon.sfsu.edu/~williams/planetsearch/planetsearch.html http://www.obspm.fr/departement/darc/planets/encycl.html http://ourworld.compuserve.com/homepages/ddgarber/main.htm (Warning: The last loads REALLY slowly because the guy has WAY too many graphics on it.) Stay groovular. ---Kristin =) From owner-starship-design Mon Oct 28 03:03 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1690" "Mon" "28" "October" "1996" "12:16:05" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "38" "starship-design: Re: Required microwave-antenna size. 100-light-year trip." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id CAA18905 for starship-design-outgoing; Mon, 28 Oct 1996 02:16:44 -0800 (PST) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id CAA18610 for ; Mon, 28 Oct 1996 02:16:20 -0800 (PST) Received: from hgl1-14.worldaccess.nl by driene.student.utwente.nl with SMTP id AA01201 (5.67b/IDA-1.5 for ); Mon, 28 Oct 1996 11:16:05 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610281016.AA01201@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1689 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Required microwave-antenna size. 100-light-year trip. Date: Mon, 28 Oct 1996 12:16:05 +0100 Kelly replied to me: >> To overcome difficulties, building it on a moon would >> not be a bad idea > >No moon is large enough, nore would any point on them have a clear view of >the ship at all times, and/or a clear view of the sun (assuming you want >solar powered. I cannot agree with both: Moons can have a clear view all the time, you are probably thinking in 2 dimensions. Think of the polar star, it never goes under the horizon (that is on most places of the Northern half of the World). So while some locations on a moon indeed won't have a clear view all the time, lots of other places on that moon will. About the size, not being large enough, that depends on what interstellar distances we want, and what wavelength we are going to use. (See today's reply to Rex.) For a clear view, in the best case we can use an entire half of a moon to build on. (In the worst case we have nothing to build on, if our destination is within the solar plane). I've even been thinking of finding an asteroid and bringing it in the optimal orbit. I know this sounds as if I'm creating a bigger problem than the initial one, but all this depends on the mass of the asteroid. Getting not too heavy asteroids in the right orbit may take far less energy than to get our starship accelerated, since its final velocities are 4 orders of magnitude lower. (8 orders less energy needed) Of course one can also build a frame of lasers, instead of a lot of loose ones (as Zenon proposed), the problem I see there is that their weight may be too little, so that gets blow away too easely by its own "photon-recoil". (I have some ideas how to get rid of this, but some are a bit complicated.) Timothy From owner-starship-design Mon Oct 28 03:11 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1718" "Mon" "28" "October" "1996" "12:16:00" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "48" "Re: starship-design: Required microwave-antenna size. 100-light-year trip." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id CAA18812 for starship-design-outgoing; Mon, 28 Oct 1996 02:16:38 -0800 (PST) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id CAA18406 for ; Mon, 28 Oct 1996 02:16:05 -0800 (PST) Received: from hgl1-14.worldaccess.nl by driene.student.utwente.nl with SMTP id AA01193 (5.67b/IDA-1.5 for ); Mon, 28 Oct 1996 11:16:00 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610281016.AA01193@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1717 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: Re: starship-design: Required microwave-antenna size. 100-light-year trip. Date: Mon, 28 Oct 1996 12:16:00 +0100 Rex wrote: >1. ANTENNA SIZE REQUIREMENT (A tutorial; read at your own risk.) >If we set the Fraunhofer-diffraction angular width equal to the >angle subtended by the sail diameter (Ds) at the range R, we can >get an expression for the diameter of the emitting antenna (De) >that is required to put "84 percent" of the emitted power within >the area of the sail: > De = 2.44 * lambda * R/Ds . > >For microwaves with lambda = 1 cm and a sail diameter of 100 km, >say, the required diameter of the emitting antenna grows 2.31 >million km for each light-year of distance to the sail, to keep >the main lobe just within the sail diameter. This is for an >antenna whose figure (shape) is correct to a fraction of a wave- >length. > >For an emitting-antenna diameter of 2.31 million km (and wave- >length of 1 cm) for a 1-lt-yr distance to the sail, the boundary >between near and far fields is at a range of about 23 thousand >lt-yr, far enough away to say we're operating in the near field. >[Note: at 1 lt-yr distance, the spot size is >(1 lt-yr/23,000 lt-yr) * 2.31 x 10^6 km = 100 km, the diameter of >the sail, as desired.] > >Are we prepared to build an expanding antenna this large? It >looks as if the M(aser)ARS should be a L(aser)ARS. For any wave- >length, however, figure control is going to remain a headache. What if lambda = 500 nm = 5E-7 m, (Blueish green) R = 10 ly = 9.46E16 m Ds = 300 km = 3E5 m Then De = 2.44 * lambda * R/Ds = 2.44 * 5E-7 * 9.46E16 / 3E5 = 3.85E5 m = 385 km range > De^2/(2.44 lambda) ---> 9.46E16<1.215E17 So we are just around the border between the near and far field. 300 and 385 kilometer diameters don't seem like a headache... Timothy From owner-starship-design Mon Oct 28 05:32 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1403" "Mon" "28" "October" "1996" "14:30:44" "+0100" "Zenon Kulpa" "zkulpa@zmit1.ippt.gov.pl" nil "32" "Re: starship-design: following the beam" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA06062 for starship-design-outgoing; Mon, 28 Oct 1996 05:32:52 -0800 (PST) Received: from zmit1.ippt.gov.pl (zmit1.ippt.gov.pl [148.81.53.40]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA05915 for ; Mon, 28 Oct 1996 05:32:39 -0800 (PST) Received: by zmit1.ippt.gov.pl (4.1/SMI-4.1) id AA00233; Mon, 28 Oct 96 14:30:44 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <9610281330.AA00233@zmit1.ippt.gov.pl> Precedence: bulk Reply-To: zkulpa@zmit1.ippt.gov.pl (Zenon Kulpa) Content-Type: text Content-Length: 1402 From: zkulpa@zmit1.ippt.gov.pl (Zenon Kulpa) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Cc: zkulpa@ippt.gov.pl Subject: Re: starship-design: following the beam Date: Mon, 28 Oct 96 14:30:44 +0100 > From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) > > I'd rather turn things around, not let the emitter follows the ship, > but let the ship follows the emitted beam. > That is a nice solution, if it shows to be possible... > The beaming station makes a "focussed" (as far as interference allows) > and beams it straight forward (in the direction of Tau Ceti). > In this case not the velocity of the orbiting station is important, > but it's acceleration (to the center of gravity), which is rather low. > Low enough for the starship to compensate and change its direction. > That is, the ship must go along the helical curve with the radius equal the radius of the beaming station orbit (assuming the plane of the orbit is perpendicular to the direction to Tau Ceti), or along a sinusoid with amplitude equal to the diameter of the orbit (assuming the direction to Tau Ceti lies within the plane of the orbit). Can somebody calculate what lateral thrust (and acceleration, amounting to a centrifugal force for the crew) will be needed for such a trajectory ? However, I wonder if the jiggle of the direction of the beam due to "directional noise" can be compensated in this way (may I recall: a tilt of the 100km diameter beaming antenna by 1/25th of an inch at the edge (i.e., a 1/100 000 000 directional error) gives a sweep of 100 000 km at 1 ly distance). -- Zenon From owner-starship-design Mon Oct 28 05:38 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2656" "Mon" "28" "October" "1996" "08:33:18" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "66" "Re: starship-design: Re: Required microwave-antenna size. 100-light-year trip." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA09958 for starship-design-outgoing; Mon, 28 Oct 1996 05:37:50 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA09889 for ; Mon, 28 Oct 1996 05:37:42 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA10250; Mon, 28 Oct 96 08:35:09 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI010076; Mon Oct 28 08:33:42 1996 Received: by most (4.1/SMI-4.1) id AA04479; Mon, 28 Oct 96 08:33:40 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma004469; Mon Oct 28 08:33:18 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA20285; Mon, 28 Oct 96 08:33:15 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 2655 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Re: Required microwave-antenna size. 100-light-year trip. Date: Mon, 28 Oct 1996 08:33:18 -0500 At 12:16 PM 10/28/96, Timothy van der Linden wrote: >Kelly replied to me: > >>> To overcome difficulties, building it on a moon would >>> not be a bad idea >> >>No moon is large enough, nore would any point on them have a clear view of >>the ship at all times, and/or a clear view of the sun (assuming you want >>solar powered. > >I cannot agree with both: > >Moons can have a clear view all the time, you are probably thinking in 2 >dimensions. Think of the polar star, it never goes under the horizon (that >is on most places of the Northern half of the World). So while some >locations on a moon indeed won't have a clear view all the time, lots of >other places on that moon will. That would of course depend on which star your going to. Few of interest are near the poles. Also I also mentioned a clear view of the ship and/or sun. Planets and moons rotate, so a solar powered maser array would have a problem in local night. >About the size, not being large enough, that depends on what interstellar >distances we want, and what wavelength we are going to use. (See today's >reply to Rex.) I was assuming Rexes antenna size limits which would be to large for any of our local moons. >For a clear view, in the best case we can use an entire half of a moon to >build on. (In the worst case we have nothing to build on, if our destination >is within the solar plane). >I've even been thinking of finding an asteroid and bringing it in the >optimal orbit. I know this sounds as if I'm creating a bigger problem than >the initial one, but all this depends on the mass of the asteroid. Getting >not too heavy asteroids in the right orbit may take far less energy than to >get our starship accelerated, since its final velocities are 4 orders of >magnitude lower. (8 orders less energy needed) >Of course one can also build a frame of lasers, instead of a lot of loose >ones (as Zenon proposed), the problem I see there is that their weight may >be too little, so that gets blow away too easely by its own "photon-recoil". >(I have some ideas how to get rid of this, but some are a bit complicated.) > > >Timothy Photo recoil is a concern given the power levels were talking about, but that assumes the transmitters aren't massive. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Mon Oct 28 05:39 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2436" "Mon" "28" "October" "1996" "08:37:21" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "66" "Re: starship-design: Required microwave-antenna size. 100-light-year trip." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA10497 for starship-design-outgoing; Mon, 28 Oct 1996 05:39:43 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA10465 for ; Mon, 28 Oct 1996 05:39:38 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA10601; Mon, 28 Oct 96 08:39:15 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI010470; Mon Oct 28 08:37:41 1996 Received: by most (4.1/SMI-4.1) id AA04551; Mon, 28 Oct 96 08:37:38 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma004547; Mon Oct 28 08:37:21 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA21122; Mon, 28 Oct 96 08:37:18 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 2435 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Required microwave-antenna size. 100-light-year trip. Date: Mon, 28 Oct 1996 08:37:21 -0500 At 12:16 PM 10/28/96, Timothy van der Linden wrote: >Rex wrote: > >>1. ANTENNA SIZE REQUIREMENT (A tutorial; read at your own risk.) > > >>If we set the Fraunhofer-diffraction angular width equal to the >>angle subtended by the sail diameter (Ds) at the range R, we can >>get an expression for the diameter of the emitting antenna (De) >>that is required to put "84 percent" of the emitted power within >>the area of the sail: >> De = 2.44 * lambda * R/Ds . >> >>For microwaves with lambda = 1 cm and a sail diameter of 100 km, >>say, the required diameter of the emitting antenna grows 2.31 >>million km for each light-year of distance to the sail, to keep >>the main lobe just within the sail diameter. This is for an >>antenna whose figure (shape) is correct to a fraction of a wave- >>length. >> >>For an emitting-antenna diameter of 2.31 million km (and wave- >>length of 1 cm) for a 1-lt-yr distance to the sail, the boundary >>between near and far fields is at a range of about 23 thousand >>lt-yr, far enough away to say we're operating in the near field. >>[Note: at 1 lt-yr distance, the spot size is >>(1 lt-yr/23,000 lt-yr) * 2.31 x 10^6 km = 100 km, the diameter of >>the sail, as desired.] >> >>Are we prepared to build an expanding antenna this large? It >>looks as if the M(aser)ARS should be a L(aser)ARS. For any wave- >>length, however, figure control is going to remain a headache. > >What if > lambda = 500 nm = 5E-7 m, (Blueish green) > R = 10 ly = 9.46E16 m > Ds = 300 km = 3E5 m >Then > De = 2.44 * lambda * R/Ds = 2.44 * 5E-7 * 9.46E16 / 3E5 = 3.85E5 m = 385 km > >range > De^2/(2.44 lambda) ---> 9.46E16<1.215E17 > >So we are just around the border between the near and far field. > > >300 and 385 kilometer diameters don't seem like a headache... > >Timothy A 300-400 kilometer laser array? Again it would be a bit hard to fit on our moon. Harder to sycronize since the frequencies are shorter. Also the sail has now gone from a wire mesh to a reflective sheet. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Mon Oct 28 05:59 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["567" "Mon" "28" "October" "1996" "08:53:20" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "19" "starship-design: New launcher." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA19666 for starship-design-outgoing; Mon, 28 Oct 1996 05:59:02 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA19563 for ; Mon, 28 Oct 1996 05:58:49 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA12126; Mon, 28 Oct 96 08:56:39 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI011928; Mon Oct 28 08:54:25 1996 Received: by most (4.1/SMI-4.1) id AA04970; Mon, 28 Oct 96 08:54:23 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma004952; Mon Oct 28 08:53:21 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA24282; Mon, 28 Oct 96 08:53:18 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 566 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: KellySt@aol.com, sdudley@ix.netcom.com, schlegel@rmc1.crocker.com, JohnFrance@aol.com, mark_jensen@cpqm.mail.saic.com, DTaylor648@aol.com, Viper7997@aol.com, starship-design@lists.uoregon.edu Subject: starship-design: New launcher. Date: Mon, 28 Oct 1996 08:53:20 -0500 Here's a site discusing a new air towed launcher concept thats gotten a contract lately. http://www.kellyspace.com/eclipse.html Kelly (No I'm not involved) ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Tue Oct 29 01:58 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["964" "Tue" "29" "October" "1996" "11:57:55" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "27" "starship-design: Laser or maser?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id BAA13572 for starship-design-outgoing; Tue, 29 Oct 1996 01:58:09 -0800 (PST) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id BAA13562 for ; Tue, 29 Oct 1996 01:58:05 -0800 (PST) Received: from slp10048.slip.utwente.nl by driene.student.utwente.nl with SMTP id AA07878 (5.67b/IDA-1.5 for ); Tue, 29 Oct 1996 10:57:52 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610290957.AA07878@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 963 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Laser or maser? Date: Tue, 29 Oct 1996 11:57:55 +0100 Kelly replied: >>300 and 385 kilometer diameters don't seem like a headache... > >A 300-400 kilometer laser array? Again it would be a bit hard to fit on >our moon. Harder to sycronize since the frequencies are shorter. Also the >sail has now gone from a wire mesh to a reflective sheet. Hard to fit on the moon? I don't understand, its diameter is 3476 kilometers. The frequency is indeed increased by a factor 3, however having a solid floor helps a lot. I wonder are semiconductor lasers more efficient and cheaper than ordinary lasers. What will be the costs compared to masers which cannot be made in semiconductors? Also on the receiving side, what are the pros and cons? On the receiver-end we not only need a mirror, but also an absorber. Are photocells better than skottky diodes? Has anyone an idea where to get this kind of information? What are the disadvantages of a reflective sheet compared to a wire mesh? Is it only the weight? Timothy From owner-starship-design Tue Oct 29 01:58 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1670" "Tue" "29" "October" "1996" "11:58:09" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "37" "starship-design: Moon/asteroid/frame" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id BAA13608 for starship-design-outgoing; Tue, 29 Oct 1996 01:58:18 -0800 (PST) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id BAA13585 for ; Tue, 29 Oct 1996 01:58:15 -0800 (PST) Received: from slp10048.slip.utwente.nl by driene.student.utwente.nl with SMTP id AA07916 (5.67b/IDA-1.5 for ); Tue, 29 Oct 1996 10:58:07 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610290958.AA07916@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1669 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Moon/asteroid/frame Date: Tue, 29 Oct 1996 11:58:09 +0100 To Kelly >>Moons can have a clear view all the time, you are probably thinking in 2 >>dimensions. Think of the polar star, it never goes under the horizon (that >>is on most places of the Northern half of the World). So while some >>locations on a moon indeed won't have a clear view all the time, lots of >>other places on that moon will. > >That would of course depend on which star your going to. Few of interest >are near the poles. Also I also mentioned a clear view of the ship and/or >sun. Planets and moons rotate, so a solar powered maser array would have a >problem in local night. That's why I suggested to put our own moon into orbid, either we pull some asteroid in a useful orbit (seems like a nice project for starters, which may even be very useful, since we may want to do that more often in the future) or we build a frame to which all lasers/masers are attached. The frame or asteroid can be given any motion around the Sun, the advantage: A 100% view of both the Sun and the destination system all the time. (The plane of rotation around the Sun will be perpendicular on the direction to the destination and the rotation time of the frame around it's own axis will be the same as its rotation time around the Sun.) >Photo recoil is a concern given the power levels were talking about, but >that assumes the transmitters aren't massive. Indeed, even an asteroid 1000 times heavier than the ship will be pushed too much, only if we use real moons recoil isn't a problem. All in all I would think a frame with lasers and photocells (or whatever) would do the best job, another advantage of frames is that there is hardly a size limit... Tim From owner-starship-design Tue Oct 29 01:58 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2150" "Tue" "29" "October" "1996" "11:58:02" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "57" "starship-design: Following the beam" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id BAA13607 for starship-design-outgoing; Tue, 29 Oct 1996 01:58:18 -0800 (PST) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id BAA13584 for ; Tue, 29 Oct 1996 01:58:14 -0800 (PST) Received: from slp10048.slip.utwente.nl by driene.student.utwente.nl with SMTP id AA07907 (5.67b/IDA-1.5 for ); Tue, 29 Oct 1996 10:58:01 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610290958.AA07907@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 2149 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Following the beam Date: Tue, 29 Oct 1996 11:58:02 +0100 Zenon replied: >> The beaming station makes a "focussed" (as far as interference allows) >> and beams it straight forward (in the direction of Tau Ceti). >> In this case not the velocity of the orbiting station is important, >> but it's acceleration (to the center of gravity), which is rather low. >> Low enough for the starship to compensate and change its direction. >> >That is, the ship must go along the helical curve with the >radius equal the radius of the beaming station orbit >(assuming the plane of the orbit is perpendicular >to the direction to Tau Ceti), or along a sinusoid >with amplitude equal to the diameter of the orbit >(assuming the direction to Tau Ceti lies within the plane >of the orbit). I would prefer a plane of orbit that is perpendicular to the direction of TC since we would not have any moments that the Sun is in the view. >Can somebody calculate what lateral thrust (and acceleration, >amounting to a centrifugal force for the crew) >will be needed for such a trajectory ? a=4 pi^2 r/T^2 (a=v^2/r v=2*pi*r/T) Where a = Acceleration in m/s^2 r = The radius of the helix in meters T = Time to make a complete orbit in seconds So say we have a beaming station on Earth: a = 4 * pi^2 * 1.5E11/(3.2E7)^2 = 6.1E-3 m/s^2 Or for the moon around the Earth: a = 4 * pi^2 * 3.84E8/(2.3E6)^2 = 2.9E-3 m/s^2 >However, I wonder if the jiggle of the direction of the beam >due to "directional noise" can be compensated in this way >(may I recall: a tilt of the 100km diameter beaming antenna >by 1/25th of an inch at the edge (i.e., a 1/100 000 000 directional error) >gives a sweep of 100 000 km at 1 ly distance). The only ways to avoid jiggling are to increase the sail/receiver or to make the sender more stable. About the stability of the laser, is a 1 millimeter jiggle not a little bit large? In fact, if we have jiggles of that size, we have to use microwaves. !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Before we go further discussing apertures/jiggles, we should first determine what resonable limits for wavelenghts will be, when we use phased arrays. Timothy From owner-starship-design Tue Oct 29 05:07 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2282" "Tue" "29" "October" "1996" "08:01:41" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "53" "Re: starship-design: Moon/asteroid/frame" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA02102 for starship-design-outgoing; Tue, 29 Oct 1996 05:07:09 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA02085 for ; Tue, 29 Oct 1996 05:06:54 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA21121; Tue, 29 Oct 96 08:04:33 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI020972; Tue Oct 29 08:03:07 1996 Received: by most (4.1/SMI-4.1) id AA02789; Tue, 29 Oct 96 08:03:01 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma002750; Tue Oct 29 08:01:44 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA05698; Tue, 29 Oct 96 08:01:41 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 2281 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Moon/asteroid/frame Date: Tue, 29 Oct 1996 08:01:41 -0500 At 11:58 AM 10/29/96, Timothy van der Linden wrote: >To Kelly > >>>Moons can have a clear view all the time, you are probably thinking in 2 >>>dimensions. Think of the polar star, it never goes under the horizon (that >>>is on most places of the Northern half of the World). So while some >>>locations on a moon indeed won't have a clear view all the time, lots of >>>other places on that moon will. >> >>That would of course depend on which star your going to. Few of interest >>are near the poles. Also I also mentioned a clear view of the ship and/or >>sun. Planets and moons rotate, so a solar powered maser array would have a >>problem in local night. > >That's why I suggested to put our own moon into orbid, either we pull some >asteroid in a useful orbit (seems like a nice project for starters, which >may even be very useful, since we may want to do that more often in the future) >or we build a frame to which all lasers/masers are attached. >The frame or asteroid can be given any motion around the Sun, the advantage: >A 100% view of both the Sun and the destination system all the time. >(The plane of rotation around the Sun will be perpendicular on the direction >to the destination and the rotation time of the frame around it's own axis >will be the same as its rotation time around the Sun.) > >>Photo recoil is a concern given the power levels were talking about, but >>that assumes the transmitters aren't massive. > >Indeed, even an asteroid 1000 times heavier than the ship will be pushed too >much, only if we use real moons recoil isn't a problem. > >All in all I would think a frame with lasers and photocells (or whatever) >would do the best job, another advantage of frames is that there is hardly a >size limit... > > >Tim Given Rex was talking about arrarys hudreds of thousands of miles across, I think a fixed structure is a no-go. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Tue Oct 29 05:13 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1986" "Tue" "29" "October" "1996" "08:10:35" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "58" "Re: starship-design: Laser or maser?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA06670 for starship-design-outgoing; Tue, 29 Oct 1996 05:13:21 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA06590 for ; Tue, 29 Oct 1996 05:13:18 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA21819; Tue, 29 Oct 96 08:12:55 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI021737; Tue Oct 29 08:12:01 1996 Received: by most (4.1/SMI-4.1) id AA03005; Tue, 29 Oct 96 08:11:55 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma002970; Tue Oct 29 08:10:36 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA07473; Tue, 29 Oct 96 08:10:34 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1985 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Laser or maser? Date: Tue, 29 Oct 1996 08:10:35 -0500 At 11:57 AM 10/29/96, Timothy van der Linden wrote: >Kelly replied: > >>>300 and 385 kilometer diameters don't seem like a headache... >> >>A 300-400 kilometer laser array? Again it would be a bit hard to fit on >>our moon. Harder to sycronize since the frequencies are shorter. Also the >>sail has now gone from a wire mesh to a reflective sheet. > >Hard to fit on the moon? I don't understand, its diameter is 3476 kilometers. >The frequency is indeed increased by a factor 3, however having a solid >floor helps a lot. If you have to find a position for the array that has constant direct line of sight at all times. Your limited to a small polar region. The farther the target star is from true north or south the narrower the polar region. Also the platforms must be in direct line of sight so they can adjust for one anothers movement (yes platforms mounted on the Moon will more around a bit). >I wonder are semiconductor lasers more efficient and cheaper than ordinary >lasers. What will be the costs compared to masers which cannot be made in >semiconductors? Can't remember. I thought free electron lasers had the highest efficency? >Also on the receiving side, what are the pros and cons? >On the receiver-end we not only need a mirror, but also an absorber. Are >photocells better than skottky diodes? Why an absorber? >Has anyone an idea where to get this kind of information? > >What are the disadvantages of a reflective sheet compared to a wire mesh? Is >it only the weight? > >Timothy Increased drag and more limits in materials I think? Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Tue Oct 29 16:03 PST 1996 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["209" "Tue" "29" "October" "1996" "19:03:01" "-0500" "Phil Bakelaar" "pbakelaar@exit109.com" "<1.5.4.32.19961030000301.007560e8@hiway1.exit109.com>" "8" "starship-design: a question?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id QAA26848 for starship-design-outgoing; Tue, 29 Oct 1996 16:03:18 -0800 (PST) Received: from hiway1.exit109.com (root@hiway1.exit109.com [205.164.176.32]) by darkwing.uoregon.edu (8.7.6/8.7.3) with ESMTP id QAA26777 for ; Tue, 29 Oct 1996 16:03:13 -0800 (PST) Received: from pbakelaar.exit109.com (ppp3-tr.exit109.com [205.164.179.130]) by hiway1.exit109.com (8.7.6/8.6.9) with SMTP id TAA14191 for ; Tue, 29 Oct 1996 19:03:16 -0500 (EST) X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <1.5.4.32.19961030000301.007560e8@hiway1.exit109.com> X-Sender: pbakelaar@hiway1.exit109.com X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Phil Bakelaar Content-Type: text/plain; charset="us-ascii" Content-Length: 208 From: Phil Bakelaar Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: a question? Date: Tue, 29 Oct 1996 19:03:01 -0500 my dad doesnt believe me... when you are in space in a vacuum with no suit, just plain skin, dont you explode, or something to that effect? (im not talking atomic bomb explosion, but you get my drift.) ben From owner-starship-design Tue Oct 29 16:06 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1535" "Tue" "29" "October" "1996" "19:06:51" "-0500" "David Levine" "David@interworld.com" nil "46" "RE: starship-design: a question?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id QAA28695 for starship-design-outgoing; Tue, 29 Oct 1996 16:06:55 -0800 (PST) Received: from www1.interworld.com (www.InterWorld.Com [165.254.130.4]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id QAA28674 for ; Tue, 29 Oct 1996 16:06:52 -0800 (PST) Received: by www1.interworld.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.993.5) id <01BBC5CC.57E9C900@www1.interworld.com>; Tue, 29 Oct 1996 19:06:52 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.993.5 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: David Levine Content-Type: text/plain; charset="us-ascii" Content-Length: 1534 From: David Levine Sender: owner-starship-design To: "'starship-design@lists.uoregon.edu'" Subject: RE: starship-design: a question? Date: Tue, 29 Oct 1996 19:06:51 -0500 Here is a definative answer from the FAQ list of sci.space: Newsgroups: sci.space Subject: Frequently Asked Questions 12/15 - Controversial Questions HOW LONG CAN A HUMAN LIVE UNPROTECTED IN SPACE If you *don't* try to hold your breath, exposure to space for half a minute or so is unlikely to produce permanent injury. Holding your breath is likely to damage your lungs, something scuba divers have to watch out for when ascending, and you'll have eardrum trouble if your Eustachian tubes are badly plugged up, but theory predicts -- and animal experiments confirm -- that otherwise, exposure to vacuum causes no immediate injury. You do not explode. Your blood does not boil. You do not freeze. You do not instantly lose consciousness. Various minor problems (sunburn, possibly "the bends", certainly some [mild, reversible, painless] swelling of skin and underlying tissue) start after ten seconds or so. At some point you lose consciousness from lack of oxygen. Injuries accumulate. After perhaps one or two minutes, you're dying. The limits are not really known. >---------- >From: Phil Bakelaar[SMTP:pbakelaar@exit109.com] >Sent: Tuesday, October 29, 1996 7:03 PM >To: starship-design@lists.uoregon.edu >Subject: starship-design: a question? > >my dad doesnt believe me... when you are in space in a vacuum >with no suit, just plain skin, dont you explode, or something >to that effect? (im not talking atomic bomb explosion, but >you get my drift.) > >ben > > From owner-starship-design Tue Oct 29 19:27 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["654" "Tue" "29" "October" "1996" "22:26:50" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "16" "Re: starship-design: a question?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id TAA20692 for starship-design-outgoing; Tue, 29 Oct 1996 19:27:19 -0800 (PST) Received: from emout13.mail.aol.com (emout13.mx.aol.com [198.81.11.39]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id TAA20677 for ; Tue, 29 Oct 1996 19:27:17 -0800 (PST) Received: by emout13.mail.aol.com (8.6.12/8.6.12) id WAA26374; Tue, 29 Oct 1996 22:26:50 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961029222649_220219187@emout13.mail.aol.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: KellySt@aol.com Content-Type: text Content-Length: 653 From: KellySt@aol.com Sender: owner-starship-design To: pbakelaar@exit109.com, starship-design@lists.uoregon.edu Subject: Re: starship-design: a question? Date: Tue, 29 Oct 1996 22:26:50 -0500 > my dad doesnt believe me... when you are in space in a > vacuum with no suit, just plain skin, dont you explode, > or something to that effect? (im not talking atomic > bomb explosion, but you get my drift.) > ben No, thats a myth. After a few minuttes your lungs ans sinuses start to dry out pretty bad, so you could ghet a hell of a nose blead and such. It would feel like the worst cheast could in your life. But if you get back into air in a few minuttes you'll be fine other than that. If you don't get back inside its the most painless death known. You pass out from oxegen loss and after 10-15 minutes you die while your out. Kelly From owner-starship-design Wed Oct 30 14:38 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["642" "Thu" "31" "October" "1996" "00:38:35" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "20" "starship-design: Re: Moon/asteroid/frame" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id OAA13349 for starship-design-outgoing; Wed, 30 Oct 1996 14:38:43 -0800 (PST) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id OAA13308 for ; Wed, 30 Oct 1996 14:38:38 -0800 (PST) Received: from hgl2-4.worldaccess.nl by driene.student.utwente.nl with SMTP id AA21540 (5.67b/IDA-1.5 for ); Wed, 30 Oct 1996 23:38:35 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610302238.AA21540@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 641 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Moon/asteroid/frame Date: Thu, 31 Oct 1996 00:38:35 +0100 Kelly replied: >>>Photo recoil is a concern given the power levels were talking about, but >>>that assumes the transmitters aren't massive. >> >>Indeed, even an asteroid 1000 times heavier than the ship will be pushed too >>much, only if we use real moons recoil isn't a problem. >> >>All in all I would think a frame with lasers and photocells (or whatever) >>would do the best job, another advantage of frames is that there is hardly a >>size limit... > >Given Rex was talking about arrarys hudreds of thousands of miles across, I >think a fixed structure is a no-go. Why can't it be a fixed frame? I don't see a problem about it. Tim From owner-starship-design Wed Oct 30 14:38 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2292" "Thu" "31" "October" "1996" "00:38:39" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "58" "Re: starship-design: Laser or maser?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id OAA13458 for starship-design-outgoing; Wed, 30 Oct 1996 14:38:50 -0800 (PST) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id OAA13316 for ; Wed, 30 Oct 1996 14:38:39 -0800 (PST) Received: from hgl2-4.worldaccess.nl by driene.student.utwente.nl with SMTP id AA21546 (5.67b/IDA-1.5 for ); Wed, 30 Oct 1996 23:38:39 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610302238.AA21546@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 2291 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: Re: starship-design: Laser or maser? Date: Thu, 31 Oct 1996 00:38:39 +0100 Kelly wrote: >>>>300 and 385 kilometer diameters don't seem like a headache... >>> >>>A 300-400 kilometer laser array? Again it would be a bit hard to fit on >>>our moon. Harder to sycronize since the frequencies are shorter. Also the >>>sail has now gone from a wire mesh to a reflective sheet. >> >>Hard to fit on the moon? I don't understand, its diameter is 3476 kilometers. >>The frequency is indeed increased by a factor 3, however having a solid >>floor helps a lot. > >If you have to find a position for the array that has constant direct line >of sight at all times. Your limited to a small polar region. The farther >the target star is from true north or south the narrower the polar region. >Also the platforms must be in direct line of sight so they can adjust for >one anothers movement (yes platforms mounted on the Moon will more around a >bit). No, that polar region is not small, it is rather big. If a star deviates 45 degrees from the rotation axis of the moon/planet, it can be seen downto the 45th longitude. (There is a small band in wich the Sun and other planets will move along (on Earth that is between +23 and -23 degrees).) >>I wonder are semiconductor lasers more efficient and cheaper than ordinary >>lasers. What will be the costs compared to masers which cannot be made in >>semiconductors? > >Can't remember. I thought free electron lasers had the highest efficency? > >>Also on the receiving side, what are the pros and cons? >>On the receiver-end we not only need a mirror, but also an absorber. Are >>photocells better than skottky diodes? > >Why an absorber? During the deceleration phase, energy is used to accelerate repulsion mass. (I know, you proposed some ingenious reflecting system, so that the EM-radiation directly accelerates the repulsion mass, but somehow that seems to ingenious.) >>Has anyone an idea where to get this kind of information? >> >>What are the disadvantages of a reflective sheet compared to a wire mesh? Is >>it only the weight? > >Increased drag and more limits in materials I think? Yes maybe, however the drag may be far less than the increased efficiency or better focusing with a smaller array. We (also others than me and Kelly) should try to find some more pros and cons about laser and maser. Timothy From owner-starship-design Wed Oct 30 15:37 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4439" "Wed" "30" "October" "1996" "17:36:25" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "119" "Re: starship-design: Laser or maser?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id PAA13015 for starship-design-outgoing; Wed, 30 Oct 1996 15:36:44 -0800 (PST) Received: from mhub2.tc.umn.edu (mhub2.tc.umn.edu [128.101.131.52]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id PAA13005 for ; Wed, 30 Oct 1996 15:36:42 -0800 (PST) Received: from maroon.tc.umn.edu by mhub2.tc.umn.edu; Wed, 30 Oct 96 17:36:29 -0600 Received: by maroon.tc.umn.edu; Wed, 30 Oct 96 17:36:28 -0600 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f In-Reply-To: <199610302238.AA21546@driene.student.utwente.nl> Message-ID: MIME-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Kevin C Houston Content-Type: TEXT/PLAIN; charset=US-ASCII Content-Length: 4438 From: Kevin C Houston Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: Re: starship-design: Laser or maser? Date: Wed, 30 Oct 1996 17:36:25 -0600 (CST) On Thu, 31 Oct 1996, Timothy van der Linden wrote: > Kelly wrote: > > >If you have to find a position for the array that has constant direct line > >of sight at all times. Your limited to a small polar region. The farther > >the target star is from true north or south the narrower the polar region. > >Also the platforms must be in direct line of sight so they can adjust for > >one anothers movement (yes platforms mounted on the Moon will more around a > >bit). Platforms need not be in direct line of sight, they must merely have an electrical connection to each other. this is especially true of Maser arrays (more on this later) > > No, that polar region is not small, it is rather big. > If a star deviates 45 degrees from the rotation axis of the moon/planet, it > can be seen downto the 45th longitude. (There is a small band in wich the > Sun and other planets will move along (on Earth that is between +23 and -23 > degrees).) > As I recall, Tau Ceti is in the southern hemisphere. Anyone know what the angle is? (I think the proper term is ascention) > >>I wonder are semiconductor lasers more efficient and cheaper than ordinary > >>lasers. What will be the costs compared to masers which cannot be made in > >>semiconductors? > > > >Can't remember. I thought free electron lasers had the highest efficency? > > > >>Also on the receiving side, what are the pros and cons? > >>On the receiver-end we not only need a mirror, but also an absorber. Are > >>photocells better than skottky diodes? No, Schottky diodes are more efficient and cheaper (eff ~ 90%) Photocells are only about 15% efficient, and that is for super high end cells. While this is not a problem in the collection of solar energy, (we can always make the solar array bigger without increasing the energy costs) such a low efficiency would be disastrous for the ship. > > > >Why an absorber? > > During the deceleration phase, energy is used to accelerate repulsion mass. > (I know, you proposed some ingenious reflecting system, so that the > EM-radiation directly accelerates the repulsion mass, but somehow that seems > to ingenious.) I have to agree with tim on this one kelly, a direct conversion to electricity to run the lineac seems the simplest. perhaps a plasma mirror will have to be considered if the wavelength is going to be so short (because the conversion eff will be so lousy) but until we rule out microwaves totally, I'd like to keep the conversion to electricity. > >>What are the disadvantages of a reflective sheet compared to a wire mesh? Is > >>it only the weight? > > > >Increased drag and more limits in materials I think? Along with drag, there is erosion. A wire mesh would allow interstellar particles to slip by, while a reflective sheet would be under constant bombardment by hydrogen atoms blowing by at nearly the speed of light > > Yes maybe, however the drag may be far less than the increased efficiency or > better focusing with a smaller array. efficiency will be less with visible light, but focusing will be better. > > We (also others than me and Kelly) should try to find some more pros and > cons about laser and maser. Pro for lasers: Cheaper to make lasers than masers. Easier to focus. Smaller arrays. Each photon has greater energy. Cons for lasers: Terrible conversion efficiency (both ends) Heavier sail with smaller holes (microscopic holes might reduce some mass) bigger redshift effects. a 7-fold decrease in wavelength for laser light will take it out of the visible spectrum. but for Masers, a 7cm beam is still usable. (that is, a beam that starts out from earth with a wavelength of 1 cm ends at the ship with a wavelength of 7cm) Pros for masers: Easier to convert to electricity (diodes vs solar cells) lighter sail with big holes (about 1 cm) Smaller redshift effects. a 7-fold decrease in wavelength for a maser beam, can still be rectified by a diode (wavelength of maser from earth ~1cm when it reaches ship, it will be 7 cm. this is still in the microwave region. Even a radio beam could be rectified by a diode and converted to electricity.) emmitters can be linked electriclly, rather than optically for lasers Cons for masers: need larger arrays. harder to focus. photons have lower energy. masers more expensive than lasers can anyone add to this list? or dispute what I've said? -- Kevin Houston http://www.urly-bird.com/ From owner-starship-design Wed Oct 30 20:57 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["8548" "Wed" "30" "October" "1996" "23:57:05" "-0500" "DotarSojat@aol.com" "DotarSojat@aol.com" nil "202" "starship-design: Beam properties, control, etc." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id UAA20297 for starship-design-outgoing; Wed, 30 Oct 1996 20:57:36 -0800 (PST) Received: from emout18.mail.aol.com (emout18.mx.aol.com [198.81.11.44]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id UAA20269 for ; Wed, 30 Oct 1996 20:57:33 -0800 (PST) Received: by emout18.mail.aol.com (8.6.12/8.6.12) id XAA10219 for starship-design@lists.uoregon.edu; Wed, 30 Oct 1996 23:57:05 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961030235703_1449243096@emout18.mail.aol.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: DotarSojat@aol.com Content-Type: text Content-Length: 8547 From: DotarSojat@aol.com Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Beam properties, control, etc. Date: Wed, 30 Oct 1996 23:57:05 -0500 Hi all On 10/24, Kelly wrote: >Questions: >How much range deviation can you tolerate? Since the beam is >being aimed at a ship you can't see in real time. You'ld have to >expect it would drift ahead or behind the exact focus spot. How >much slack is allowed? > >What is the lateral deviation of the beam? I.E. whats the power >per m^2 in the center vs the edge of the focused spot? The diff- >erences would distort the sail and alter the ships course and >acceleration. > >As mentioned above, how precicely can we measure the possition of >an object floating in space? Assuming each microwave emmiter >platform has laser ranging info to each/some of the others. Can >you get the nessisary possitional accuracy? (Within a couple >MM?) Note you don't need to control the position that accurate- >ly, just know what it is so you can compensate for it. On 10/24, Zenon wrote: >However, if the platform moves along the Sun-centered orbit, its >velocity is of the order of tens of kilometers a second..., hence >it must compensate for its change of position with appropriate >change of orientation, and the latter must be VERY accurate... On 10/26, Timothy wrote: >I'd rather turn things around, not let the emitter follows the >ship, but let the ship follows the emitted beam. >The beaming station makes a "focussed" (as far as interference >allows) an beams it straight forward (in the direction of Tau >Ceti.) >In this case not the velocity of the orbiting station is impor- >tant, but it's acceleration (to the center of gravity), which is >rather low. Low enough for the starship to compensate and change >its direction. On 10/28, Zenon wrote: >That is, the ship must go along the helical curve with the radius >equal the radius of the beaming station orbit (assuming the plane >of the orbit is perpendicular to the direction of Tau Ceti), or >along a sinusoid with amplitude equal to the diameter of the >orbit (assuming the direction to Tau Ceti lies within the plane >of the orbit). > >... > >However, I wonder if the jiggle of the direction of the beam due >to "directional noise" can be compensated in this way... On 10/28, Timothy wrote: >What if > lambda = 500 nm = 5E-7 m, (Blueish green) > R = 10 ly = 9.46E16 m > Ds = 300 km = 3E5 m >... >300 and 385 kilometer diameters don't seem like a headache... In recapitulation, questions/observations above address issues of 1. Depth of focus 2. Power distribution in beam spot 3. Antenna figure sensing/control 4. Pointing control a. Direction: to ship or to destination b. Orbital motion of antenna platform c. "Jitter" 5. Sail/ship guidance 6. Effects of reduced wavelength While I normally prefer to keep my contribution to helping define the tools available to calculate performance (with some example results), I may be able to help here with some facts/opinions. So, in the order itemized above: 1. Depth of focus Assume the beam from a 2.31E6-km-diameter microwave antenna is focused to a sail (beam-spot) diameter of 100 km at a distance of 1 lt-yr. At the distance from the focus that the beam cross-sec- tion has grown from the area at the focus by 10 percent (power per unit area reduced by about 10 percent), say, the radius of the beam has grown by 100 km * [sqrt(1.1) - 1]/2, or about 2.4 km. The distance from the focus for that growth is (2.4/2.31E6) * 1 lt-yr, or approximately 1E-6 lt-yr. So, the sail/ship has to stay within about 1.E-6 lt-yr of the focus to keep the power from dropping off by more than 10 percent. 2. Power distribution in beam spot If the sail/ship is in the near field of the beam-forming aperture, then the radial power distribution is given by Fresnel diffraction: the envelope of the intensity across the spot is "flat" (the profile is rectangular), with alternating narrow con- centric rings of dark and light. As the sail approaches the boundary to the far field, the radial distribution of intensity morphs into the approximately-Gaussian profile of the Fraunhofer diffraction pattern. I wouldn't want to undertake the calculation of the actual power distribution at any arbitrary range. Assuming it's flat for our purposes is probably adequate. 3. Antenna figure sensing/control I don't have any detailed information at my fingertips in this area, but what superficial information I do have indicates that this problem should not be a show-stopper. (A lot of work has been done on phased arrays of both antennas and mirror segments; some of it pertains to fine beam steering, also.) I believe this problem is of far lesser import than achieving the required large sizes of antennas/mirrors. 4. Pointing compensations a. Direction: to ship or to destination I believe Timothy has made the case for pointing the beam at the destination star quite well. Let the sail/ship steer to stay in the beam (see below). b. Orbital motion of antenna platform As Timothy calculates in his 10/29 note for a beaming station in Solar orbit at the distance of the Earth, the maximum lateral acceleration to follow a helical or sinusoidal interstellar path of that amplitude and period would be about 6E-4 gs. This means that the sail must control its attitude (tilt) through not much more than about 1E-3 radians to follow the desired path. c. "Jitter" One of the losses to be considered in depositing a lethal fluence from a laser weapon on a target is the effect of fairly-high-fre- quency, small-amplitude oscillatory motions of the beam axis about the desired direction, called "jitter" (Zenon's "jiggles," or "directional noise"). The frequencies are generally higher than about 100Hz, and the amplitudes, with today's technology, are less than a microradian. This motion is the result of such things as correction cycles and mechanical vibrations. This is a random process that lends itself to averaging. The intensity at any point on the spot is given by folding together the beam profile and a time-average of the deflection vs time of the beam direc- tion. On the other hand, with extremely large antenna/mirror arrays, the frequency may be so low that deflections could be measured in real time. These measurements could be introduced as correction inputs to an electronic fine-pointing-control (element- phasing) system for the array. 5. Sail/ship guidance The sail/ship can have outriggers beyond the edge of the sail to sense the edge of the beam and provide steering-correction inputs to adjust the tilt of the sail to stay at the radial center of the beam. The acceleration of the sail/ship will depend on its distance from the focus. (Operating in the near field has some advantages). A computer simulation of the sail/ship's motion based on a power level reduced by a safety factor from that at the focus can be made to provide a projected safe position of the sail/ship at any time. If the focus is placed behind the projected safe position of the sail/ship during the actual flight, any lag in acceleration of the sail below the "safe" level will drop it back closer to the focus where the power is greater. The higher power there will drive it forward again toward the safe position, in a stable control condition at a power level between full (at the focus) and "safe." (I think I might have described this better if I had first written the control equation and observed its effects in a simulation.) 6. Effects of reduced wavelength (some already covered by Timothy/ Kelly/Kevin) While reducing the wavelength of the radiation in the beam to that of blue-green light allows the required aperture to be reduced to "only" 385 km, the "antenna" becomes a mirror. A mirror has the problem (among others) of maintaining its reflectivity over long periods in the presence of hazards of the space environment such as micrometeoroid erosion. In partial answer to Timothy's question of 10/29 regarding effic- iency of lasers, I seem to recall efficiencies of about 30 percent, 10 percent and 5 percent for chemical, solid-state and gas-dynamic lasers, respectively. (There's nothing in the Grolier Encyclopedia about the efficiencies of different lasers, except a mention that CO2 electric lasers have efficiencies in the 15-30 percent range; I don't have any references for any other lasers than chemical lasers, the favorite of weapons developers.) Conversion of light energy to electrical energy at any reasonable efficiency probably involves a thermodynamic cycle. (Heat engines are about twice as efficient as the best solar cells.) Rex From owner-starship-design Thu Oct 31 05:15 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3613" "Thu" "31" "October" "1996" "15:15:02" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "86" "starship-design: Re: Laser or maser?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA00918 for starship-design-outgoing; Thu, 31 Oct 1996 05:15:42 -0800 (PST) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA00355 for ; Thu, 31 Oct 1996 05:15:17 -0800 (PST) Received: from hengelo20.pop.tip.nl by driene.student.utwente.nl with SMTP id AA22398 (5.67b/IDA-1.5 for ); Thu, 31 Oct 1996 14:14:58 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199610311314.AA22398@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 3612 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Laser or maser? Date: Thu, 31 Oct 1996 15:15:02 +0100 Kevin Wrote: >Platforms need not be in direct line of sight, they must merely have an >electrical connection to each other. this is especially true of Maser arrays >(more on this later) I know, but it would probably easier to have the energy supply (Solar-receivers) and masers at the same place. >> No, that polar region is not small, it is rather big. >> If a star deviates 45 degrees from the rotation axis of the moon/planet, it >> can be seen downto the 45th longitude. (There is a small band in wich the >> Sun and other planets will move along (on Earth that is between +23 and -23 >> degrees).) > >As I recall, Tau Ceti is in the southern hemisphere. Anyone know what >the angle is? (I think the proper term is ascention) Its ascention is 16 degrees (74 degrees deviation from the axis), so we hardly could have made a worse choice. So maybe we should rethink... >> >>I wonder are semiconductor lasers more efficient and cheaper than ordinary >> >>lasers. What will be the costs compared to masers which cannot be made in >> >>semiconductors? >> > >> >Can't remember. I thought free electron lasers had the highest efficency? >> > >> >>Also on the receiving side, what are the pros and cons? >> >>On the receiver-end we not only need a mirror, but also an absorber. Are >> >>photocells better than skottky diodes? > >No, Schottky diodes are more efficient and cheaper (eff ~ 90%) Photocells >are only about 15% efficient, and that is for super high end cells. While >this is not a problem in the collection of solar energy, (we can always >make the solar array bigger without increasing the energy costs) such >a low efficiency would be disastrous for the ship. I think the efficiency of photocells is a bit decreased by the fact that photons with low energy (Infrared ?) don't contribute to the electrical current. However I have no idea if this is really true and how much the efficiency is influenced by that. >> >Why an absorber? >> >> During the deceleration phase, energy is used to accelerate repulsion mass. >> (I know, you proposed some ingenious reflecting system, so that the >> EM-radiation directly accelerates the repulsion mass, but somehow that seems >> to ingenious.) > >I have to agree with tim on this one kelly, a direct conversion to >electricity to run the lineac seems the simplest. perhaps a plasma >mirror will have to be considered if the wavelength is going to >be so short (because the conversion eff will be so lousy) but until >we rule out microwaves totally, I'd like to keep the conversion to >electricity. Hey, we should use microwaves of 2.45 MHz, that way we could directly power a steam engine ;) >>>What are the disadvantages of a reflective sheet compared to a wire >>>mesh? Is it only the weight? >> >>Increased drag and more limits in materials I think? > >Along with drag, there is erosion. A wire mesh would allow interstellar >particles to slip by, while a reflective sheet would be under constant >bombardment by hydrogen atoms blowing by at nearly the speed of light Of course a sheet has a bigger surface as a mesh, however if the mesh needs to be bigger... (To be fair, I don't think the one covers the other.) >> We (also others than me and Kelly) should try to find some more pros and >> cons about laser and maser. Thanks for the list. If solar-pumped lasers can work, they may even be cheaper. I don't think the redshift effects will be dramatic, most mirrors for visible light also work for parts of infra-red. I do not understand why "laser-photons having more energy" is an advantage... Timothy From owner-starship-design Thu Oct 31 05:31 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1298" "Thu" "31" "October" "1996" "08:26:48" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "39" "Re: starship-design: Re: Moon/asteroid/frame" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA02598 for starship-design-outgoing; Thu, 31 Oct 1996 05:31:27 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA02588 for ; Thu, 31 Oct 1996 05:31:22 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA19166; Thu, 31 Oct 96 08:31:00 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI019059; Thu Oct 31 08:28:14 1996 Received: by most (4.1/SMI-4.1) id AA03865; Thu, 31 Oct 96 08:28:12 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma003827; Thu Oct 31 08:26:50 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA02791; Thu, 31 Oct 96 08:26:47 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1297 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Re: Moon/asteroid/frame Date: Thu, 31 Oct 1996 08:26:48 -0500 At 12:38 AM 10/31/96, Timothy van der Linden wrote: >Kelly replied: > >>>>Photo recoil is a concern given the power levels were talking about, but >>>>that assumes the transmitters aren't massive. >>> >>>Indeed, even an asteroid 1000 times heavier than the ship will be pushed too >>>much, only if we use real moons recoil isn't a problem. >>> >>>All in all I would think a frame with lasers and photocells (or whatever) >>>would do the best job, another advantage of frames is that there is hardly a >>>size limit... >> >>Given Rex was talking about arrarys hudreds of thousands of miles across, I >>think a fixed structure is a no-go. > >Why can't it be a fixed frame? I don't see a problem about it. > >Tim A fixed frame hudreds of thousands of miles across? Aside from problems of structural strength, and lack of stiffness. What planet would you convert into the framework? Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Thu Oct 31 05:33 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2947" "Thu" "31" "October" "1996" "08:29:22" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "80" "Re: starship-design: Laser or maser?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA02710 for starship-design-outgoing; Thu, 31 Oct 1996 05:33:32 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA02699 for ; Thu, 31 Oct 1996 05:33:27 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA19347; Thu, 31 Oct 96 08:32:54 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI019157; Thu Oct 31 08:30:53 1996 Received: by most (4.1/SMI-4.1) id AA03947; Thu, 31 Oct 96 08:30:50 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma003895; Thu Oct 31 08:29:24 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA03124; Thu, 31 Oct 96 08:29:21 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 2946 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Laser or maser? Date: Thu, 31 Oct 1996 08:29:22 -0500 At 12:38 AM 10/31/96, Timothy van der Linden wrote: >Kelly wrote: > >>>>>300 and 385 kilometer diameters don't seem like a headache... >>>> >>>>A 300-400 kilometer laser array? Again it would be a bit hard to fit on >>>>our moon. Harder to sycronize since the frequencies are shorter. Also the >>>>sail has now gone from a wire mesh to a reflective sheet. >>> >>>Hard to fit on the moon? I don't understand, its diameter is 3476 kilometers. >>>The frequency is indeed increased by a factor 3, however having a solid >>>floor helps a lot. >> >>If you have to find a position for the array that has constant direct line >>of sight at all times. Your limited to a small polar region. The farther >>the target star is from true north or south the narrower the polar region. >>Also the platforms must be in direct line of sight so they can adjust for >>one anothers movement (yes platforms mounted on the Moon will more around a >>bit). > >No, that polar region is not small, it is rather big. >If a star deviates 45 degrees from the rotation axis of the moon/planet, it >can be seen downto the 45th longitude. (There is a small band in wich the >Sun and other planets will move along (on Earth that is between +23 and -23 >degrees).) If it needs to have same-time visibility to the ship and the sun it cuts things down a bit. >>>I wonder are semiconductor lasers more efficient and cheaper than ordinary >>>lasers. What will be the costs compared to masers which cannot be made in >>>semiconductors? >> >>Can't remember. I thought free electron lasers had the highest efficency? >> >>>Also on the receiving side, what are the pros and cons? >>>On the receiver-end we not only need a mirror, but also an absorber. Are >>>photocells better than skottky diodes? >> >>Why an absorber? > >During the deceleration phase, energy is used to accelerate repulsion mass. >(I know, you proposed some ingenious reflecting system, so that the >EM-radiation directly accelerates the repulsion mass, but somehow that seems >to ingenious.) Ah, I wasn't considering a MARS System >>>Has anyone an idea where to get this kind of information? >>> >>>What are the disadvantages of a reflective sheet compared to a wire mesh? Is >>>it only the weight? >> >>Increased drag and more limits in materials I think? > >Yes maybe, however the drag may be far less than the increased efficiency or >better focusing with a smaller array. > >We (also others than me and Kelly) should try to find some more pros and >cons about laser and maser. > >Timothy Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Thu Oct 31 05:44 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5811" "Thu" "31" "October" "1996" "08:41:01" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "160" "Re: starship-design: Laser or maser?" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA03738 for starship-design-outgoing; Thu, 31 Oct 1996 05:44:04 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA03724 for ; Thu, 31 Oct 1996 05:43:57 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA19898; Thu, 31 Oct 96 08:43:52 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI019810; Thu Oct 31 08:42:02 1996 Received: by most (4.1/SMI-4.1) id AA04213; Thu, 31 Oct 96 08:41:59 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma004193; Thu Oct 31 08:41:04 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA04941; Thu, 31 Oct 96 08:41:01 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 5810 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: Kevin C Houston Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Laser or maser? Date: Thu, 31 Oct 1996 08:41:01 -0500 At 5:36 PM 10/30/96, Kevin C Houston wrote: >On Thu, 31 Oct 1996, Timothy van der Linden wrote: > >> Kelly wrote: >> >> >If you have to find a position for the array that has constant direct line >> >of sight at all times. Your limited to a small polar region. The farther >> >the target star is from true north or south the narrower the polar region. >> >Also the platforms must be in direct line of sight so they can adjust for >> >one anothers movement (yes platforms mounted on the Moon will more around a >> >bit). > >Platforms need not be in direct line of sight, they must merely have an >electrical connection to each other. this is especially true of Maser arrays >(more on this later) ?? How do you do laser ranging and positioning without line of sight? Thou timing can be done by cable. >> No, that polar region is not small, it is rather big. >> If a star deviates 45 degrees from the rotation axis of the moon/planet, it >> can be seen downto the 45th longitude. (There is a small band in wich the >> Sun and other planets will move along (on Earth that is between +23 and -23 >> degrees).) >> > >As I recall, Tau Ceti is in the southern hemisphere. Anyone know what >the angle is? (I think the proper term is ascention) Alpha Centauri is in the souther hemisphere to. Is this a conspiracy? ;) >> >>I wonder are semiconductor lasers more efficient and cheaper than ordinary >> >>lasers. What will be the costs compared to masers which cannot be made in >> >>semiconductors? >> > >> >Can't remember. I thought free electron lasers had the highest efficency? >> > >> >>Also on the receiving side, what are the pros and cons? >> >>On the receiver-end we not only need a mirror, but also an absorber. Are >> >>photocells better than skottky diodes? > >No, Schottky diodes are more efficient and cheaper (eff ~ 90%) Photocells >are only about 15% efficient, and that is for super high end cells. While >this is not a problem in the collection of solar energy, (we can always >make the solar array bigger without increasing the energy costs) such >a low efficiency would be disastrous for the ship. > >> > >> >Why an absorber? >> >> During the deceleration phase, energy is used to accelerate repulsion mass. >> (I know, you proposed some ingenious reflecting system, so that the >> EM-radiation directly accelerates the repulsion mass, but somehow that seems >> to ingenious.) > >I have to agree with tim on this one kelly, a direct conversion to >electricity to run the lineac seems the simplest. perhaps a plasma >mirror will have to be considered if the wavelength is going to >be so short (because the conversion eff will be so lousy) but until >we rule out microwaves totally, I'd like to keep the conversion to >electricity. I hadn't been considering a MARS system. A plasma Mirror wouldn't work with lasers though. Then again you could use a laser pumped rocket with pretty high spec impulse. If you could keep from melting the ship. MARS question! How much tonage of electrical cable would it take to carry the amount of power we're talking about? Could this be a limiting factor? >> >>What are the disadvantages of a reflective sheet compared to >> >>a wire mesh? Is it only the weight? >> > >> >Increased drag and more limits in materials I think? > >Along with drag, there is erosion. A wire mesh would allow interstellar >particles to slip by, while a reflective sheet would be under constant >bombardment by hydrogen atoms blowing by at nearly the speed of light > >> >> Yes maybe, however the drag may be far less than the increased efficiency or >> better focusing with a smaller array. > >efficiency will be less with visible light, but focusing will be better. Might be better. But the optics would have to be more precise. Slight rippling in the saiol could be more of a problem. >> We (also others than me and Kelly) should try to find some more pros and >> cons about laser and maser. > > >Pro for lasers: >Cheaper to make lasers than masers. >Easier to focus. >Smaller arrays. >Each photon has greater energy. > >Cons for lasers: >Terrible conversion efficiency (both ends) >Heavier sail with smaller holes (microscopic holes might reduce some mass) >bigger redshift effects. > a 7-fold decrease in wavelength for laser light will take it out > of the visible spectrum. but for Masers, a 7cm beam is still > usable. (that is, a beam that starts out from earth with a > wavelength of 1 cm ends at the ship with a wavelength of 7cm) Safty concern. I think its easier to shield from microwaves then lasers. Could be important to folks in the back of the ship. ;) >Pros for masers: >Easier to convert to electricity (diodes vs solar cells) >lighter sail with big holes (about 1 cm) >Smaller redshift effects. > a 7-fold decrease in wavelength for a maser beam, can still > be rectified by a diode (wavelength of maser from earth ~1cm > when it reaches ship, it will be 7 cm. this is still in the > microwave region. Even a radio beam could be rectified by > a diode and converted to electricity.) >emmitters can be linked electriclly, rather than optically for lasers > >Cons for masers: >need larger arrays. >harder to focus. >photons have lower energy. >masers more expensive than lasers > > >can anyone add to this list? or dispute what I've said? > >-- >Kevin Houston http://www.urly-bird.com/ Looks good for me. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Thu Oct 31 06:32 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2810" "Thu" "31" "October" "1996" "09:32:47" "-0500" "David Levine" "David@interworld.com" nil "66" "starship-design: Television Starships" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id GAA16872 for starship-design-outgoing; Thu, 31 Oct 1996 06:32:41 -0800 (PST) Received: from www1.interworld.com (www.InterWorld.Com [165.254.130.4]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id GAA16860 for ; Thu, 31 Oct 1996 06:32:39 -0800 (PST) Received: by www1.interworld.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.993.5) id <01BBC70E.7AB9FF20@www1.interworld.com>; Thu, 31 Oct 1996 09:32:48 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.993.5 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: David Levine Content-Type: text/plain; charset="us-ascii" Content-Length: 2809 From: David Levine Sender: owner-starship-design To: "'starship-design@lists.uoregon.edu'" Cc: "'duncan@mail.cable.com'" Subject: starship-design: Television Starships Date: Thu, 31 Oct 1996 09:32:47 -0500 Hi, gang, just forwarding this along. Duncan is not a member of the starship design mailing list, so if you respond, you'll want to cc him. Duncan, these questions are more easily answered by the group. I can give you at least one fast answer: no, we do not have the ability to produce a starship -today- that can accellerate at 1g for several years. There are, however, other ways to produce gravity. And communication is the -least- of our worries. It's the drive system that causes all the engineering headaches. David ------------------------------------------------------------- >From duncan@mail.cable.com Wed Oct 30 10:26 EST 1996 Comments: Authenticated sender is From: "Duncan McKenzie" To: lunar@sunsite.unc.edu Date: Wed, 30 Oct 1996 10:26:57 +0000 MIME-Version: 1.0 Content-transfer-encoding: 7BIT Subject: Starship designs Hi David I'm a freelance writer currently working on a proposal for a TV series set on a starship in the near future. My objective here is to create something entertaining but scientifically plausible. Plots would explore the challenges of having a crew living in a state of confined isolation during a single, long mission (to a nearby star), rather than the usual space battles and alien encounters. In order to make this easy to produce, I want the crew to be living in a normal gravity -- hopefully on flat floors. It seems to me that the only way to accomplish this is to accelerate the starship at a constant 1g. Would it be possible, using current technology, to build engines capable of delivering this level of thrust continuously over several years? I would also like the spacecraft to be quite small, with all food water and air being recycled (again over many years). Are there any practical proposals for how this recycling might be done? I thought that the methods used on nuclear submarines might apply here, but apparently they just compress and store their garbage and waste products. What I'm after is a complete, self-contained ecosystem, with humans (a crew of six) as a part of the system, but I'm having trouble finding details as to exactly what species would be required. Finally, what are the practical limits on how far away a spacecraft could communicate with Earth? I see that the T.A.U. design on your web site is supposed to communicate with Earth from interstellar space by means of a 10 W laser. Is this a practical proposal? I find it extraordinary that a laser could be aligned accurately enough to operate over such a distance. Do you know how far into "interstellar space" such a device would be able to maintain contact? I'd be grateful for any help you can give me on this, or for other sources of information you can point me to. Thanks. Duncan McKenzie Toronto, Canada From owner-starship-design Thu Oct 31 06:38 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["10055" "Thu" "31" "October" "1996" "09:13:04" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "244" "Re: starship-design: Beam properties, control, etc." "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id GAA17372 for starship-design-outgoing; Thu, 31 Oct 1996 06:38:30 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id GAA17360 for ; Thu, 31 Oct 1996 06:38:23 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA21850; Thu, 31 Oct 96 09:16:07 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI021816; Thu Oct 31 09:15:06 1996 Received: by most (4.1/SMI-4.1) id AA05008; Thu, 31 Oct 96 09:15:04 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma004938; Thu Oct 31 09:13:07 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA09489; Thu, 31 Oct 96 09:13:03 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 10054 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: DotarSojat@aol.com Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Beam properties, control, etc. Date: Thu, 31 Oct 1996 09:13:04 -0500 At 11:57 PM 10/30/96, DotarSojat@aol.com wrote: >Hi all > >On 10/24, Kelly wrote: > >>Questions: >>How much range deviation can you tolerate? Since the beam is >>being aimed at a ship you can't see in real time. You'ld have to >>expect it would drift ahead or behind the exact focus spot. How >>much slack is allowed? >> >>What is the lateral deviation of the beam? I.E. whats the power >>per m^2 in the center vs the edge of the focused spot? The diff- >>erences would distort the sail and alter the ships course and >>acceleration. >> >>As mentioned above, how precicely can we measure the possition of >>an object floating in space? Assuming each microwave emmiter >>platform has laser ranging info to each/some of the others. Can >>you get the nessisary possitional accuracy? (Within a couple >>MM?) Note you don't need to control the position that accurate- >>ly, just know what it is so you can compensate for it. > >On 10/24, Zenon wrote: > >>However, if the platform moves along the Sun-centered orbit, its >>velocity is of the order of tens of kilometers a second..., hence >>it must compensate for its change of position with appropriate >>change of orientation, and the latter must be VERY accurate... > >On 10/26, Timothy wrote: > >>I'd rather turn things around, not let the emitter follows the >>ship, but let the ship follows the emitted beam. >>The beaming station makes a "focussed" (as far as interference >>allows) an beams it straight forward (in the direction of Tau >>Ceti.) >>In this case not the velocity of the orbiting station is impor- >>tant, but it's acceleration (to the center of gravity), which is >>rather low. Low enough for the starship to compensate and change >>its direction. > >On 10/28, Zenon wrote: > >>That is, the ship must go along the helical curve with the radius >>equal the radius of the beaming station orbit (assuming the plane >>of the orbit is perpendicular to the direction of Tau Ceti), or >>along a sinusoid with amplitude equal to the diameter of the >>orbit (assuming the direction to Tau Ceti lies within the plane >>of the orbit). >> >>... >> >>However, I wonder if the jiggle of the direction of the beam due >>to "directional noise" can be compensated in this way... > >On 10/28, Timothy wrote: > >>What if >> lambda = 500 nm = 5E-7 m, (Blueish green) >> R = 10 ly = 9.46E16 m >> Ds = 300 km = 3E5 m >>... >>300 and 385 kilometer diameters don't seem like a headache... > >In recapitulation, questions/observations above address issues of > 1. Depth of focus > 2. Power distribution in beam spot > 3. Antenna figure sensing/control > 4. Pointing control > a. Direction: to ship or to destination > b. Orbital motion of antenna platform > c. "Jitter" > 5. Sail/ship guidance > 6. Effects of reduced wavelength > >While I normally prefer to keep my contribution to helping define >the tools available to calculate performance (with some example >results), I may be able to help here with some facts/opinions. > >So, in the order itemized above: > >1. Depth of focus > >Assume the beam from a 2.31E6-km-diameter microwave antenna is >focused to a sail (beam-spot) diameter of 100 km at a distance of >1 lt-yr. At the distance from the focus that the beam cross-sec- >tion has grown from the area at the focus by 10 percent (power per >unit area reduced by about 10 percent), say, the radius of the >beam has grown by 100 km * [sqrt(1.1) - 1]/2, or about 2.4 km. >The distance from the focus for that growth is (2.4/2.31E6) * >1 lt-yr, or approximately 1E-6 lt-yr. > >So, the sail/ship has to stay within about 1.E-6 lt-yr of the >focus to keep the power from dropping off by more than 10 percent. I read that as about 10,000,000 kilometers, or 32 light secounds. Not a lot of slack over interstellar distences. A sligh sail problem could have you well out of that pretty quickly. >2. Power distribution in beam spot > >If the sail/ship is in the near field of the beam-forming >aperture, then the radial power distribution is given by Fresnel >diffraction: the envelope of the intensity across the spot is >"flat" (the profile is rectangular), with alternating narrow con- >centric rings of dark and light. As the sail approaches the >boundary to the far field, the radial distribution of intensity >morphs into the approximately-Gaussian profile of the Fraunhofer >diffraction pattern. I wouldn't want to undertake the calculation >of the actual power distribution at any arbitrary range. Assuming >it's flat for our purposes is probably adequate. Hum, I would have expected interfearence and lensing to have a greater effect then that. This is good news. >3. Antenna figure sensing/control > >I don't have any detailed information at my fingertips in this >area, but what superficial information I do have indicates that >this problem should not be a show-stopper. (A lot of work has >been done on phased arrays of both antennas and mirror segments; >some of it pertains to fine beam steering, also.) I believe this >problem is of far lesser import than achieving the required large >sizes of antennas/mirrors. Probably true. The problem is in the budget not the tech. ;) >4. Pointing compensations > a. Direction: to ship or to destination > >I believe Timothy has made the case for pointing the beam at the >destination star quite well. Let the sail/ship steer to stay in >the beam (see below). > > b. Orbital motion of antenna platform > >As Timothy calculates in his 10/29 note for a beaming station in >Solar orbit at the distance of the Earth, the maximum lateral >acceleration to follow a helical or sinusoidal interstellar path >of that amplitude and period would be about 6E-4 gs. This means >that the sail must control its attitude (tilt) through not much >more than about 1E-3 radians to follow the desired path. > > c. "Jitter" > >One of the losses to be considered in depositing a lethal fluence >from a laser weapon on a target is the effect of fairly-high-fre- >quency, small-amplitude oscillatory motions of the beam axis about >the desired direction, called "jitter" (Zenon's "jiggles," or >"directional noise"). The frequencies are generally higher than >about 100Hz, and the amplitudes, with today's technology, are less >than a microradian. This motion is the result of such things as >correction cycles and mechanical vibrations. This is a random >process that lends itself to averaging. The intensity at any >point on the spot is given by folding together the beam profile >and a time-average of the deflection vs time of the beam direc- >tion. On the other hand, with extremely large antenna/mirror >arrays, the frequency may be so low that deflections could be >measured in real time. These measurements could be introduced as >correction inputs to an electronic fine-pointing-control (element- >phasing) system for the array. > >5. Sail/ship guidance > >The sail/ship can have outriggers beyond the edge of the sail to >sense the edge of the beam and provide steering-correction inputs >to adjust the tilt of the sail to stay at the radial center of the >beam. > >The acceleration of the sail/ship will depend on its distance from >the focus. (Operating in the near field has some advantages). A >computer simulation of the sail/ship's motion based on a power >level reduced by a safety factor from that at the focus can be >made to provide a projected safe position of the sail/ship at any >time. > >If the focus is placed behind the projected safe position of the >sail/ship during the actual flight, any lag in acceleration of the >sail below the "safe" level will drop it back closer to the focus >where the power is greater. The higher power there will drive it >forward again toward the safe position, in a stable control >condition at a power level between full (at the focus) and "safe." > >(I think I might have described this better if I had first written >the control equation and observed its effects in a simulation.) We had, long ago, been discusing small automated scout craft to be sent ahead of the main ship to look for debries and stuff. They could also scout out the beam boarders and report to the main ship. Being smaller they could have a better sail to weight ratio, which would make them less vulnerable to low power levels at the fringe. >6. Effects of reduced wavelength (some already covered by Timothy/ >Kelly/Kevin) > >While reducing the wavelength of the radiation in the beam to that >of blue-green light allows the required aperture to be reduced >to "only" 385 km, the "antenna" becomes a mirror. A mirror has >the problem (among others) of maintaining its reflectivity over >long periods in the presence of hazards of the space environment >such as micrometeoroid erosion. > >In partial answer to Timothy's question of 10/29 regarding effic- >iency of lasers, I seem to recall efficiencies of about 30 >percent, 10 percent and 5 percent for chemical, solid-state and >gas-dynamic lasers, respectively. (There's nothing in the Grolier >Encyclopedia about the efficiencies of different lasers, except a >mention that CO2 electric lasers have efficiencies in the 15-30 >percent range; I don't have any references for any other lasers >than chemical lasers, the favorite of weapons developers.) > >Conversion of light energy to electrical energy at any reasonable >efficiency probably involves a thermodynamic cycle. (Heat engines >are about twice as efficient as the best solar cells.) > >Rex A thermal engine processing e18th of power? Good work up Rex. We might want to pull a lot of this stuff into a web page for the site. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Thu Oct 31 07:21 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4451" "Thu" "31" "October" "1996" "10:17:27" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "112" "Re: starship-design: Television Starships" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id HAA01558 for starship-design-outgoing; Thu, 31 Oct 1996 07:21:30 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id HAA01517 for ; Thu, 31 Oct 1996 07:21:17 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA26788; Thu, 31 Oct 96 10:20:41 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI026667; Thu Oct 31 10:19:12 1996 Received: by most (4.1/SMI-4.1) id AA06750; Thu, 31 Oct 96 10:19:06 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma006700; Thu Oct 31 10:17:29 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA21254; Thu, 31 Oct 96 10:17:27 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 4450 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: David Levine Cc: "'starship-design@lists.uoregon.edu'" , "duncan@mail.cable.com" Subject: Re: starship-design: Television Starships Date: Thu, 31 Oct 1996 10:17:27 -0500 At 9:32 AM 10/31/96, David Levine wrote: >Hi, gang, just forwarding this along. Duncan is not a member >of the starship design mailing list, so if you respond, you'll >want to cc him. > >Duncan, these questions are more easily answered by the group. >I can give you at least one fast answer: no, we do not have >the ability to produce a starship -today- that can accellerate >at 1g for several years. There are, however, other ways to >produce gravity. And communication is the -least- of our >worries. It's the drive system that causes all the engineering >headaches. > >David > >------------------------------------------------------------- >>From duncan@mail.cable.com Wed Oct 30 10:26 EST 1996 >Comments: Authenticated sender is >From: "Duncan McKenzie" >To: lunar@sunsite.unc.edu >Date: Wed, 30 Oct 1996 10:26:57 +0000 >MIME-Version: 1.0 >Content-transfer-encoding: 7BIT >Subject: Starship designs > >Hi David > >I'm a freelance writer currently working on a proposal for a TV >series set on a starship in the near future. My objective here is to >create something entertaining but scientifically plausible. Plots >would explore the challenges of having a crew living in a state of >confined isolation during a single, long mission (to a nearby star), >rather than the usual space battles and alien encounters. Hum, one of our arguments was over how the crew would deal with years of nothing to do while on route. Presumably the bulk of the crew would be there to explore the starsystem, so they would have little to do enroute >In order to make this easy to produce, I want the crew to be living in >a normal gravity -- hopefully on flat floors. It seems to me that the >only way to accomplish this is to accelerate the starship at a >constant 1g. Would it be possible, using current technology, to build >engines capable of delivering this level of thrust continuously over >several years? If you'ld check our newer draft versions for the web site at http://165.254.130.90/LIT/index.html or http://www.urly-bird.com/LIT/ They have some illistrations of the interiors. Fraid they tend to be big pipes aranged in a circle and spun and twisted to adjust for different gravty/thrust conditions. I worked them up, so write me if you terminally confused. ;) >I would also like the spacecraft to be quite small, with all food >water and air being recycled (again over many years). Are there any >practical proposals for how this recycling might be done? I thought >that the methods used on nuclear submarines might apply here, but >apparently they just compress and store their garbage and waste >products. What I'm after is a complete, self-contained ecosystem, with >humans (a crew of six) as a part of the system, but I'm having trouble >finding details as to exactly what species would be required. We have a big argumant on that, also written up on the newer (in work sites). If your missions less then 30-40 years it save weight by just bringing along frozen and dryied food and such. Water and air recycling makes sence, and is fairly striagt forward. One idea that might photo graph well is clear plastic pipes about 6-10 inches in diameter (?) Filled with oxegen producing alge in a well lit room. As you pump the mess around you pump in CO2 and let out Oxegen. Dead alge serve as mulch for new alge. >Finally, what are the practical limits on how far away a spacecraft >could communicate with Earth? I see that the T.A.U. design on your web >site is supposed to communicate with Earth from interstellar space by >means of a 10 W laser. Is this a practical proposal? I find it >extraordinary that a laser could be aligned accurately enough to >operate over such a distance. Do you know how far into "interstellar >space" such a device would be able to maintain contact? > >I'd be grateful for any help you can give me on this, or for other >sources of information you can point me to. > >Thanks. > >Duncan McKenzie >Toronto, Canada Good luck Duncan Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Thu Oct 31 08:21 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1685" "Thu" "31" "October" "1996" "11:21:24" "-0500" "David Levine" "David@interworld.com" nil "50" "starship-design: RE: Television Starships" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA22886 for starship-design-outgoing; Thu, 31 Oct 1996 08:21:23 -0800 (PST) Received: from www1.interworld.com (www.InterWorld.Com [165.254.130.4]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA22867 for ; Thu, 31 Oct 1996 08:21:21 -0800 (PST) Received: by www1.interworld.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.993.5) id <01BBC71D.A706CB80@www1.interworld.com>; Thu, 31 Oct 1996 11:21:25 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.993.5 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: David Levine Content-Type: text/plain; charset="us-ascii" Content-Length: 1684 From: David Levine Sender: owner-starship-design To: "'duncan@cable.com'" , "'starship-design@lists.uoregon.edu'" Subject: starship-design: RE: Television Starships Date: Thu, 31 Oct 1996 11:21:24 -0500 Yes, what you mention about small spinning ships is true. One way around this is to divide the ship into two sections, separate them on a tether, and spin the whole system. The tether could be however long you want it. You could have an elevator running along the length of the tether, etc. No, the mailing list is for everyone - I don't think there are many aerospace engineers at all! I don't remember the subscribe text, but my guess is you send email to majordomo@darkwing.uoregon.edu with the phrase "susbcribe starship-design" in the body of the message. David >---------- >From: Duncan McKenzie[SMTP:duncan@mail.cable.com] >Sent: Thursday, October 31, 1996 6:11 AM >To: David Levine >Subject: Re: Television Starships > >Hi David > >Thanks for your help on this. > >I would actually be interested in joining your mailing list (partly >because of this project, but also because I'm interested in the >subject). Is it just for professional aerospace engineers, or are >laypersons also welcome? > >> There are, however, other ways to >> produce gravity. > >I considered a spinning ship (or section thereof) for this project, >but it seemed to me that either the ship would have to be very large >(which goes against the dramatic goal of making it feel very >confined), or the floors would be very curved (to avoid objects >rolling off to the corners). Also, I had a hunch that a smaller, >fast-spinning ship might lead to health problems, since the >"downward" pull on the blood in the feet would be significantly less >than the pull on the blood in the brain. > >Are there other ways? (Other than, say, Velcro shoes) > >Thanks again for your help. > >Duncan > From owner-starship-design Thu Oct 31 08:57 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2862" "Thu" "31" "October" "1996" "11:54:28" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "84" "Re: starship-design: RE: Television Starships" "^From:" nil nil "10" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id IAA01756 for starship-design-outgoing; Thu, 31 Oct 1996 08:57:31 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id IAA01721 for ; Thu, 31 Oct 1996 08:57:22 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA04600; Thu, 31 Oct 96 11:56:35 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI004476; Thu Oct 31 11:55:12 1996 Received: by most (4.1/SMI-4.1) id AA09215; Thu, 31 Oct 96 11:55:01 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma009198; Thu Oct 31 11:54:30 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA08895; Thu, 31 Oct 96 11:54:28 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 2861 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: David Levine Cc: "duncan@cable.com" , "starship-design@lists.uoregon.edu" Subject: Re: starship-design: RE: Television Starships Date: Thu, 31 Oct 1996 11:54:28 -0500 At 11:21 AM 10/31/96, David Levine wrote: >Yes, what you mention about small spinning ships is true. >One way around this is to divide the ship into two sections, >separate them on a tether, and spin the whole system. >The tether could be however long you want it. You could >have an elevator running along the length of the tether, etc. >No, the mailing list is for everyone - I don't think there are >many aerospace engineers at all! Well their are a few ex NASA folks. But we have a bit of everything and are quite informal, and undisaplined. As to a teather. At higher speeds the teather has problems with erosion, and radiation. The later is a big issue for passengers in the transfer 'vator. ;) >I don't remember the subscribe text, but my guess is you >send email to majordomo@darkwing.uoregon.edu with >the phrase "susbcribe starship-design" in the body of the >message. > >David > > >>---------- >>From: Duncan McKenzie[SMTP:duncan@mail.cable.com] >>Sent: Thursday, October 31, 1996 6:11 AM >>To: David Levine >>Subject: Re: Television Starships >> >>Hi David >> >>Thanks for your help on this. >> >>I would actually be interested in joining your mailing list (partly >>because of this project, but also because I'm interested in the >>subject). Is it just for professional aerospace engineers, or are >>laypersons also welcome? >> >>> There are, however, other ways to >>> produce gravity. >> >>I considered a spinning ship (or section thereof) for this project, >>but it seemed to me that either the ship would have to be very large >>(which goes against the dramatic goal of making it feel very >>confined), or the floors would be very curved (to avoid objects >>rolling off to the corners). Also, I had a hunch that a smaller, >>fast-spinning ship might lead to health problems, since the >>"downward" pull on the blood in the feet would be significantly less >>than the pull on the blood in the brain. Whatever spins should be 600 feet across or so. Smaller and you could get motion sick from the rotation rates. As long as the load on your body is about 1G the rest of your body is happy. Given the huge bulk of fuel needed for a flight, thats not hard to come up with. You could spin the ship end over end? A lot depends on the engines you want to assume. Which is why thats still a big argument for us. >>Are there other ways? (Other than, say, Velcro shoes) >> >>Thanks again for your help. >> >>Duncan >> Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Fri Nov 1 20:11 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["387" "Fri" "1" "November" "1996" "23:11:11" "-0500" "Phil Bakelaar" "pbakelaar@exit109.com" nil "12" "starship-design: irc & ai anyone?" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id UAA08073 for starship-design-outgoing; Fri, 1 Nov 1996 20:11:41 -0800 (PST) Received: from hiway1.exit109.com (root@hiway1.exit109.com [205.164.176.32]) by darkwing.uoregon.edu (8.7.6/8.7.3) with ESMTP id UAA08022 for ; Fri, 1 Nov 1996 20:11:39 -0800 (PST) Received: from pbakelaar.exit109.com (ppp34-tr.exit109.com [205.164.179.163]) by hiway1.exit109.com (8.7.6/8.6.9) with SMTP id XAA21922 for ; Fri, 1 Nov 1996 23:11:41 -0500 (EST) X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <1.5.4.32.19961102041111.0074abac@hiway1.exit109.com> X-Sender: pbakelaar@hiway1.exit109.com X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Phil Bakelaar Content-Type: text/plain; charset="us-ascii" Content-Length: 386 From: Phil Bakelaar Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: irc & ai anyone? Date: Fri, 01 Nov 1996 23:11:11 -0500 i met this person recently on irc who wanted to start an irc channel on artificial intelligence... he has 7 of 10 signatures (in this case, email addresses) he needs.. if any of you are interested, email abegun@gnn.com for details and to sign your name.. he knows the name of the channel, i think it will be #artificialintelligence (dont ask me) and it will be on the undernet.. ben From owner-starship-design Sat Nov 2 07:26 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1323" "Sat" "2" "November" "1996" "17:26:38" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "38" "starship-design: Clear view" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id HAA21683 for starship-design-outgoing; Sat, 2 Nov 1996 07:26:37 -0800 (PST) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id HAA21674 for ; Sat, 2 Nov 1996 07:26:35 -0800 (PST) Received: from hengelo04.pop.tip.nl by driene.student.utwente.nl with SMTP id AA01479 (5.67b/IDA-1.5 for ); Sat, 2 Nov 1996 16:26:34 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199611021526.AA01479@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1322 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Clear view Date: Sat, 02 Nov 1996 17:26:38 +0100 Kelly replied: >>>>All in all I would think a frame with lasers and photocells (or whatever) >>>>would do the best job, another advantage of frames is that there is hardly a >>>>size limit... >>> >>>Given Rex was talking about arrarys hudreds of thousands of miles across, I >>>think a fixed structure is a no-go. >> >>Why can't it be a fixed frame? I don't see a problem about it. > >A fixed frame hudreds of thousands of miles across? Aside from problems of >structural strength, and lack of stiffness. What planet would you convert >into the framework? There are enough asteroids around to get the necessary materials from. About lack of stiffness and structural strength, I guess that depends on the way the array is constructed. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Kelly replied: >>No, that polar region is not small, it is rather big. >>If a star deviates 45 degrees from the rotation axis of the moon/planet, it >>can be seen downto the 45th longitude. (There is a small band in wich the >>Sun and other planets will move along (on Earth that is between +23 and -23 >>degrees).) > >If it needs to have same-time visibility to the ship and the sun it cuts >things down a bit. True, this sceme was mainly meant for a clear view on the destination system. Timothy From owner-starship-design Sat Nov 2 09:08 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1028" "Sat" "2" "November" "1996" "19:08:28" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "26" "starship-design: Re: Laser or maser?" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id JAA12988 for starship-design-outgoing; Sat, 2 Nov 1996 09:08:28 -0800 (PST) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id JAA12936 for ; Sat, 2 Nov 1996 09:08:25 -0800 (PST) Received: from hengelo10.pop.tip.nl by driene.student.utwente.nl with SMTP id AA05010 (5.67b/IDA-1.5 for ); Sat, 2 Nov 1996 18:08:22 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199611021708.AA05010@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1027 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Laser or maser? Date: Sat, 02 Nov 1996 19:08:28 +0100 Kelly replied to Kevin: >MARS question! How much tonage of electrical cable would it take to carry >the amount of power we're talking about? Could this be a limiting factor? It may even be that we should start thinking of a direct maser/laser to accelerated particle engine. For example you'd make a pipe with a small exhaust pipe at one side and a window transparant for light on the other side, the particles inside will get heated up and flow out through the exhaust end. Of course this needs an elaborate mirroring system to get that huge beam into a few small pipes. >>> Yes maybe, however the drag may be far less than the increased efficiency or >>> better focusing with a smaller array. >> >>efficiency will be less with visible light, but focusing will be better. > >Might be better. But the optics would have to be more precise. Slight >rippling in the saiol could be more of a problem. The sail does not have to focus (I hope), so ripples will only bring us of course, which could be easely corrected. Tim From owner-starship-design Sat Nov 2 16:09 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4256" "Sun" "3" "November" "1996" "02:09:15" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "96" "starship-design: Re: Beam properties, control, etc." "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id QAA20038 for starship-design-outgoing; Sat, 2 Nov 1996 16:09:19 -0800 (PST) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id QAA20029 for ; Sat, 2 Nov 1996 16:09:14 -0800 (PST) Received: from hengelo22.pop.tip.nl by driene.student.utwente.nl with SMTP id AA16923 (5.67b/IDA-1.5 for ); Sun, 3 Nov 1996 01:09:14 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199611030009.AA16923@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 4255 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Beam properties, control, etc. Date: Sun, 03 Nov 1996 02:09:15 +0100 Rex wrote a small summary of problems: >1. Depth of focus > >Assume the beam from a 2.31E6-km-diameter microwave antenna is >focused to a sail (beam-spot) diameter of 100 km at a distance of >1 lt-yr. At the distance from the focus that the beam cross-sec- >tion has grown from the area at the focus by 10 percent (power per >unit area reduced by about 10 percent), say, the radius of the >beam has grown by 100 km * [sqrt(1.1) - 1]/2, or about 2.4 km. >The distance from the focus for that growth is (2.4/2.31E6) * >1 lt-yr, or approximately 1E-6 lt-yr. > >So, the sail/ship has to stay within about 1.E-6 lt-yr of the >focus to keep the power from dropping off by more than 10 percent. Hmmm, how smart of me (not so). All the time I was thinking of an almost parallel beam (as far as interference allows) instead of one that is focused at a certain point. This means that the starship should not just follow the beam, but more precisely it should follow the focussing point. I also thought of the following: How bright can we make our laser/maser array? How many Watts per square meter is realistic? Does this also limit the minimal size? >4. Pointing compensations > a. Direction: to ship or to destination > >I believe Timothy has made the case for pointing the beam at the >destination star quite well. Let the sail/ship steer to stay in >the beam (see below). The last few days we've been writing and thinking about this, I think that the beaming station could make things easier for the ship by focussing on an as straight possible track. Of course it can not sense where the ship is, but it should just focus along a predestined path. The ship would still needs to take care of staying just in front of the focuspoint of the beam. To make this possible there should be a small overcapacity in the system, so that when the ship would drift off, there would be enough power to get back on track. And thus when it was at the focuspoint, it would not use all the power available. >5. Sail/ship guidance > >The sail/ship can have outriggers beyond the edge of the sail to >sense the edge of the beam and provide steering-correction inputs >to adjust the tilt of the sail to stay at the radial center of the >beam. > >The acceleration of the sail/ship will depend on its distance from >the focus. (Operating in the near field has some advantages). A >computer simulation of the sail/ship's motion based on a power >level reduced by a safety factor from that at the focus can be >made to provide a projected safe position of the sail/ship at any >time. Yes, every radial deviation from the center will push the ship further away from the center. The pressure on one side of the sail will become less than on the other side, this means the sail (and the ship) will turn/tilt. Unfortunately the way in which the sail will be tilted, will make things even worse. >If the focus is placed behind the projected safe position of the >sail/ship during the actual flight, any lag in acceleration of the >sail below the "safe" level will drop it back closer to the focus >where the power is greater. The higher power there will drive it >forward again toward the safe position, in a stable control >condition at a power level between full (at the focus) and "safe." To bad we can't make the sides of the beam more intense than the center, that would create a minimum, which would automatically keep the ship in the beam. >(I think I might have described this better if I had first written >the control equation and observed its effects in a simulation.) > >6. Effects of reduced wavelength (some already covered by Timothy/ >Kelly/Kevin) > >While reducing the wavelength of the radiation in the beam to that >of blue-green light allows the required aperture to be reduced >to "only" 385 km, the "antenna" becomes a mirror. A mirror has >the problem (among others) of maintaining its reflectivity over >long periods in the presence of hazards of the space environment >such as micrometeoroid erosion. True, therefore it would be interesting to know how much micrometeoroids would exist in interstellar space. However, since we have a smaller mirror it may be easier to shield it on the back side(=the non reflecting side, pointing to TC). Tim From owner-starship-design Sat Nov 2 16:09 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1210" "Sun" "3" "November" "1996" "02:09:22" "+0100" "Timothy van der Linden" "TLG.van.der.Linden@tip.nl" nil "30" "starship-design: Re: Beam properties, control, etc." "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id QAA20081 for starship-design-outgoing; Sat, 2 Nov 1996 16:09:31 -0800 (PST) Received: from driene.student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id QAA20047 for ; Sat, 2 Nov 1996 16:09:22 -0800 (PST) Received: from hengelo22.pop.tip.nl by driene.student.utwente.nl with SMTP id AA16926 (5.67b/IDA-1.5 for ); Sun, 3 Nov 1996 01:09:21 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199611030009.AA16926@driene.student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1209 From: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Beam properties, control, etc. Date: Sun, 03 Nov 1996 02:09:22 +0100 Kelly replied to Rex: >>1. Depth of focus >> >>Assume the beam from a 2.31E6-km-diameter microwave antenna is >>focused to a sail (beam-spot) diameter of 100 km at a distance of >>1 lt-yr. At the distance from the focus that the beam cross-sec- >>tion has grown from the area at the focus by 10 percent (power per >>unit area reduced by about 10 percent), say, the radius of the >>beam has grown by 100 km * [sqrt(1.1) - 1]/2, or about 2.4 km. >>The distance from the focus for that growth is (2.4/2.31E6) * >>1 lt-yr, or approximately 1E-6 lt-yr. >> >>So, the sail/ship has to stay within about 1.E-6 lt-yr of the >>focus to keep the power from dropping off by more than 10 percent. > >I read that as about 10,000,000 kilometers, or 32 light secounds. Not a >lot of slack over interstellar distences. A sligh sail problem could have >you well out of that pretty quickly. True, it would be a tight schedule: One minute too late at a certain place and you have missed the beam for good. Sailing on a beam means inherently that every second of the trip is planned, slight deviations are allowed, but will be risky. A sail may sound as an easy "engine", but you better have a good captain/navigator. Tim From owner-starship-design Mon Nov 4 05:33 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1507" "Mon" "4" "November" "1996" "08:27:45" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "40" "Re: starship-design: Clear view" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA03836 for starship-design-outgoing; Mon, 4 Nov 1996 05:32:08 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA03820 for ; Mon, 4 Nov 1996 05:32:04 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA12184; Mon, 4 Nov 96 08:31:58 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI011997; Mon Nov 4 08:30:05 1996 Received: by most (4.1/SMI-4.1) id AA04917; Mon, 4 Nov 96 08:30:00 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma004840; Mon Nov 4 08:27:45 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA19251; Mon, 4 Nov 96 08:27:43 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1506 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Clear view Date: Mon, 4 Nov 1996 08:27:45 -0500 At 5:26 PM 11/2/96, Timothy van der Linden wrote: >Kelly replied: > >>>>>All in all I would think a frame with lasers and photocells (or whatever) >>>>>would do the best job, another advantage of frames is that there is >>>>>hardly a >>>>>size limit... >>>> >>>>Given Rex was talking about arrarys hudreds of thousands of miles across, I >>>>think a fixed structure is a no-go. >>> >>>Why can't it be a fixed frame? I don't see a problem about it. >> >>A fixed frame hudreds of thousands of miles across? Aside from problems of >>structural strength, and lack of stiffness. What planet would you convert >>into the framework? > >There are enough asteroids around to get the necessary materials from. >About lack of stiffness and structural strength, I guess that depends on the >way the array is constructed. Its still not practical to try to build a solid structure the size of a jovian planet. It wound be stiff, and will have a lot of trouble with tidal forces. Its simpler and cheaper to just have a lose swarm of syncronized transmitter platforms that wander around as need be. >Timothy ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Mon Nov 4 05:34 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1705" "Mon" "4" "November" "1996" "08:29:39" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "48" "Re: starship-design: Re: Laser or maser?" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA03996 for starship-design-outgoing; Mon, 4 Nov 1996 05:34:46 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA03987 for ; Mon, 4 Nov 1996 05:34:42 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA12465; Mon, 4 Nov 96 08:34:35 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI012194; Mon Nov 4 08:32:02 1996 Received: by most (4.1/SMI-4.1) id AA04982; Mon, 4 Nov 96 08:31:59 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma004902; Mon Nov 4 08:29:40 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA19718; Mon, 4 Nov 96 08:29:37 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1704 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Re: Laser or maser? Date: Mon, 4 Nov 1996 08:29:39 -0500 At 7:08 PM 11/2/96, Timothy van der Linden wrote: >Kelly replied to Kevin: > >>MARS question! How much tonage of electrical cable would it take to carry >>the amount of power we're talking about? Could this be a limiting factor? > >It may even be that we should start thinking of a direct maser/laser to >accelerated particle engine. >For example you'd make a pipe with a small exhaust pipe at one side and a >window transparant for light on the other side, the particles inside will >get heated up and flow out through the exhaust end. Of course this needs an >elaborate mirroring system to get that huge beam into a few small pipes. Given the power levels were talking about that could vaporize the ship unless the insulation was perfect. >>>> Yes maybe, however the drag may be far less than the increased >>>>efficiency or >>>> better focusing with a smaller array. >>> >>>efficiency will be less with visible light, but focusing will be better. >> >>Might be better. But the optics would have to be more precise. Slight >>rippling in the saiol could be more of a problem. > >The sail does not have to focus (I hope), so ripples will only bring us of >course, which could be easely corrected. > >Tim For a MARS system you might need to focus the sail to concentrate the power. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Mon Nov 4 06:27 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1762" "Mon" "4" "November" "1996" "09:23:13" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "45" "Re: starship-design: Re: Beam properties, control, etc." "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id GAA17278 for starship-design-outgoing; Mon, 4 Nov 1996 06:27:18 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id GAA17265 for ; Mon, 4 Nov 1996 06:27:15 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA16499; Mon, 4 Nov 96 09:27:06 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI016308; Mon Nov 4 09:25:05 1996 Received: by most (4.1/SMI-4.1) id AA06689; Mon, 4 Nov 96 09:25:02 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma006630; Mon Nov 4 09:23:15 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA29095; Mon, 4 Nov 96 09:23:12 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1761 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Re: Beam properties, control, etc. Date: Mon, 4 Nov 1996 09:23:13 -0500 At 2:09 AM 11/3/96, Timothy van der Linden wrote: >Kelly replied to Rex: > >>>1. Depth of focus >>> >>>Assume the beam from a 2.31E6-km-diameter microwave antenna is >>>focused to a sail (beam-spot) diameter of 100 km at a distance of >>>1 lt-yr. At the distance from the focus that the beam cross-sec- >>>tion has grown from the area at the focus by 10 percent (power per >>>unit area reduced by about 10 percent), say, the radius of the >>>beam has grown by 100 km * [sqrt(1.1) - 1]/2, or about 2.4 km. >>>The distance from the focus for that growth is (2.4/2.31E6) * >>>1 lt-yr, or approximately 1E-6 lt-yr. >>> >>>So, the sail/ship has to stay within about 1.E-6 lt-yr of the >>>focus to keep the power from dropping off by more than 10 percent. >> >>I read that as about 10,000,000 kilometers, or 32 light secounds. Not a >>lot of slack over interstellar distences. A sligh sail problem could have >>you well out of that pretty quickly. > >True, it would be a tight schedule: One minute too late at a certain place >and you have missed the beam for good. >Sailing on a beam means inherently that every second of the trip is planned, >slight deviations are allowed, but will be risky. A sail may sound as an >easy "engine", but you better have a good captain/navigator. > > >Tim Starting to sound like walking a muti light year tight rope. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Tue Nov 5 02:57 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1272" "Tue" "5" "November" "1996" "12:57:25" "+0100" "Timothy van der Linden" "TLG.van.der.Linden@tip.nl" nil "29" "starship-design: Tight rope" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id CAA20302 for starship-design-outgoing; Tue, 5 Nov 1996 02:57:24 -0800 (PST) Received: from parijs.tip.nl (parijs.tip.nl [143.177.1.10]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id CAA20293 for ; Tue, 5 Nov 1996 02:57:22 -0800 (PST) Received: from hengelo13.pop.tip.nl by parijs.tip.nl with smtp (Smail3.1.29.1 #16) id m0vKjGQ-000DnLC; Tue, 5 Nov 96 12:01 MET X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: X-Sender: t596675@pop1.tip.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1271 From: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Tight rope Date: Tue, 05 Nov 1996 12:57:25 +0100 >>>>So, the sail/ship has to stay within about 1.E-6 lt-yr of the >>>>focus to keep the power from dropping off by more than 10 percent. >>> >>>I read that as about 10,000,000 kilometers, or 32 light secounds. Not a >>>lot of slack over interstellar distences. A sligh sail problem could have >>>you well out of that pretty quickly. >> >>True, it would be a tight schedule: One minute too late at a certain place >>and you have missed the beam for good. >>Sailing on a beam means inherently that every second of the trip is planned, >>slight deviations are allowed, but will be risky. A sail may sound as an >>easy "engine", but you better have a good captain/navigator. > >Starting to sound like walking a muti light year tight rope. Yes, it is, getting out of the helical movement is not the worst thing, since the rotational acceleration is rather low, but the forward acceleration is not. One engine failure for an hour and we have to drift forever. I see only two solutions, build a reserve engine based on fusion (or whatever) so that in case of emergency a short (1 week?) burst can be accomplished. Or make the beam parallel, I wonder if this is possible when we make the receiving and emitting antenna the same size. Rex, can you confirm if this works? Tim From owner-starship-design Tue Nov 5 02:57 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["965" "Tue" "5" "November" "1996" "12:57:22" "+0100" "Timothy van der Linden" "TLG.van.der.Linden@tip.nl" nil "23" "starship-design: Tidal forces" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id CAA20313 for starship-design-outgoing; Tue, 5 Nov 1996 02:57:28 -0800 (PST) Received: from parijs.tip.nl (parijs.tip.nl [143.177.1.10]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id CAA20304 for ; Tue, 5 Nov 1996 02:57:25 -0800 (PST) Received: from hengelo13.pop.tip.nl by parijs.tip.nl with smtp (Smail3.1.29.1 #16) id m0vKjGN-000DleC; Tue, 5 Nov 96 12:01 MET X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: X-Sender: t596675@pop1.tip.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 964 From: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Tidal forces Date: Tue, 05 Nov 1996 12:57:22 +0100 >>>>Why can't it be a fixed frame? I don't see a problem about it. >>> >>>A fixed frame hudreds of thousands of miles across? Aside from problems of >>>structural strength, and lack of stiffness. What planet would you convert >>>into the framework? >> >>There are enough asteroids around to get the necessary materials from. >>About lack of stiffness and structural strength, I guess that depends on the >>way the array is constructed. > >Its still not practical to try to build a solid structure the size of a >jovian planet. It wound be stiff, and will have a lot of trouble with >tidal forces. Its simpler and cheaper to just have a lose swarm of >syncronized transmitter platforms that wander around as need be. What tidal forces?, in orbit around the Sun the gravitational pull from other planets is minimal. (In fact the gravitational pull from the Sun on planets is already very low, for Mercury the acceleration towards the Sun is only 0.004g) Tim From owner-starship-design Tue Nov 5 05:57 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1657" "Tue" "5" "November" "1996" "08:55:28" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "41" "Re: starship-design: Tidal forces" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA28559 for starship-design-outgoing; Tue, 5 Nov 1996 05:57:50 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA28547 for ; Tue, 5 Nov 1996 05:57:47 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA29600; Tue, 5 Nov 96 08:57:38 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI029462; Tue Nov 5 08:56:09 1996 Received: by most (4.1/SMI-4.1) id AA03704; Tue, 5 Nov 96 08:56:06 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma003679; Tue Nov 5 08:55:30 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA13126; Tue, 5 Nov 96 08:55:26 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1656 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Tidal forces Date: Tue, 5 Nov 1996 08:55:28 -0500 At 12:57 PM 11/5/96, Timothy van der Linden wrote: >>>>>Why can't it be a fixed frame? I don't see a problem about it. >>>> >>>>A fixed frame hudreds of thousands of miles across? Aside from problems of >>>>structural strength, and lack of stiffness. What planet would you convert >>>>into the framework? >>> >>>There are enough asteroids around to get the necessary materials from. >>>About lack of stiffness and structural strength, I guess that depends on the >>>way the array is constructed. >> >>Its still not practical to try to build a solid structure the size of a >>jovian planet. It wound be stiff, and will have a lot of trouble with >>tidal forces. Its simpler and cheaper to just have a lose swarm of >>syncronized transmitter platforms that wander around as need be. > >What tidal forces?, in orbit around the Sun the gravitational pull from >other planets is minimal. >(In fact the gravitational pull from the Sun on planets is already very low, >for Mercury the acceleration towards the Sun is only 0.004g) > >Tim Tidal forces varry acording to size. Given a structure a dozen times the size of earth (and extrenmly unlikelt situation) it would have larger tidal force. Certainly enough to keep it edge on to the sun. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Tue Nov 5 09:47 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1211" "Tue" "5" "November" "1996" "12:43:05" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "26" "starship-design: Light RamScoop?" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id JAA15095 for starship-design-outgoing; Tue, 5 Nov 1996 09:47:53 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id JAA14726 for ; Tue, 5 Nov 1996 09:47:31 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA22894; Tue, 5 Nov 96 12:46:43 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI022559; Tue Nov 5 12:43:47 1996 Received: by most (4.1/SMI-4.1) id AA09706; Tue, 5 Nov 96 12:43:43 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma009687; Tue Nov 5 12:43:06 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA27332; Tue, 5 Nov 96 12:43:03 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1210 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Cc: kellyst@aol.com (Kelly Starks AOL account) Subject: starship-design: Light RamScoop? Date: Tue, 5 Nov 1996 12:43:05 -0500 A thought. Long ago, we were discusing Ramscoops. Eiather for ram fussion systems, or ram augmented systems. The later could use interstallar dust to augment the reaction mass. At the time we figured that any physical scoop would weigh more then the material it scooped up, and ran into papers (Heppinhimer wrote one) that suggested that the the drag from a magnetic scoop would be greater than the thrust. What about light scoops? Could we use lasers reflected off of outriding light sails? The sails would need to tack back and forth on the beem. But could reflect the beam back in toward the line of flight. Pushing material inward toward a smaller scoop. This would seem to avoid the drag problem, but I've no idea if they would be worth the trouble. Kelly, your scout for new angles. ;) ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Wed Nov 6 09:55 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1125" "Wed" "6" "November" "1996" "19:54:16" "+0100" "Timothy van der Linden" "TLG.van.der.Linden@tip.nl" nil "27" "starship-design: Re: Tidal forces" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id JAA28046 for starship-design-outgoing; Wed, 6 Nov 1996 09:55:26 -0800 (PST) Received: from parijs.tip.nl (parijs.tip.nl [143.177.1.10]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id JAA27879 for ; Wed, 6 Nov 1996 09:55:20 -0800 (PST) Received: from hengelo12.pop.tip.nl by parijs.tip.nl with smtp (Smail3.1.29.1 #16) id m0vLCFL-000DnAC; Wed, 6 Nov 96 18:58 MET X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: X-Sender: t596675@pop1.tip.nl (Unverified) X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1124 From: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Tidal forces Date: Wed, 06 Nov 1996 19:54:16 +0100 To Kelly >>>Its still not practical to try to build a solid structure the size of a >>>jovian planet. It wound be stiff, and will have a lot of trouble with >>>tidal forces. Its simpler and cheaper to just have a lose swarm of >>>syncronized transmitter platforms that wander around as need be. >> >>What tidal forces?, in orbit around the Sun the gravitational pull from >>other planets is minimal. >>(In fact the gravitational pull from the Sun on planets is already very low, >>for Mercury the acceleration towards the Sun is only 0.004g) > >Tidal forces varry acording to size. Given a structure a dozen times the >size of earth (and extrenmly unlikelt situation) it would have larger tidal >force. Certainly enough to keep it edge on to the sun. Why? Can you use a description without using "tidal forces"? That term seems not so adequate here. I understand that part that are at different distances from the Sun will have a different gravitational pull, but believe me these differences are REALLY small. You cannot compare those forces to those which a meteor experiences when flying close by a planet. Tim From owner-starship-design Wed Nov 6 09:55 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1048" "Wed" "6" "November" "1996" "19:54:19" "+0100" "Timothy van der Linden" "TLG.van.der.Linden@tip.nl" nil "26" "starship-design: Re: Light RamScoop?" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id JAA28213 for starship-design-outgoing; Wed, 6 Nov 1996 09:55:30 -0800 (PST) Received: from parijs.tip.nl (parijs.tip.nl [143.177.1.10]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id JAA28041 for ; Wed, 6 Nov 1996 09:55:26 -0800 (PST) Received: from hengelo12.pop.tip.nl by parijs.tip.nl with smtp (Smail3.1.29.1 #16) id m0vLCFP-000DlEC; Wed, 6 Nov 96 18:58 MET X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: X-Sender: t596675@pop1.tip.nl (Unverified) X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1047 From: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Light RamScoop? Date: Wed, 06 Nov 1996 19:54:19 +0100 To Kelly >A thought. Long ago, we were discusing Ramscoops. Eiather for ram fussion >systems, or ram augmented systems. The later could use interstallar dust >to augment the reaction mass. At the time we figured that any physical >scoop would weigh more then the material it scooped up, and ran into papers >(Heppinhimer wrote one) that suggested that the the drag from a magnetic >scoop would be greater than the thrust. > >What about light scoops? Could we use lasers reflected off of outriding >light sails? The sails would need to tack back and forth on the beem. But >could reflect the beam back in toward the line of flight. Pushing material >inward toward a smaller scoop. This would seem to avoid the drag problem, >but I've no idea if they would be worth the trouble. Where does the laser come from? If it comes from the ship, it will push the ship back. At the moment I can't ask more detailed questions, since I'm not 100% sure of the configuration. For example how are you going to "tack the sail back to the ship"? Tim From owner-starship-design Wed Nov 6 10:28 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1711" "Wed" "6" "November" "1996" "13:24:04" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "44" "Re: starship-design: Re: Tidal forces" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id KAA18690 for starship-design-outgoing; Wed, 6 Nov 1996 10:28:07 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id KAA18100 for ; Wed, 6 Nov 1996 10:27:48 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA10593; Wed, 6 Nov 96 13:27:13 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI010410; Wed Nov 6 13:25:17 1996 Received: by most (4.1/SMI-4.1) id AA10022; Wed, 6 Nov 96 13:25:12 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma009987; Wed Nov 6 13:24:06 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA22557; Wed, 6 Nov 96 13:24:03 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1710 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Re: Tidal forces Date: Wed, 6 Nov 1996 13:24:04 -0500 At 7:54 PM 11/6/96, Timothy van der Linden wrote: >To Kelly > >>>>Its still not practical to try to build a solid structure the size of a >>>>jovian planet. It wound be stiff, and will have a lot of trouble with >>>>tidal forces. Its simpler and cheaper to just have a lose swarm of >>>>syncronized transmitter platforms that wander around as need be. >>> >>>What tidal forces?, in orbit around the Sun the gravitational pull from >>>other planets is minimal. >>>(In fact the gravitational pull from the Sun on planets is already very low, >>>for Mercury the acceleration towards the Sun is only 0.004g) >> >>Tidal forces varry acording to size. Given a structure a dozen times the >>size of earth (and extrenmly unlikelt situation) it would have larger tidal >>force. Certainly enough to keep it edge on to the sun. > >Why? Can you use a description without using "tidal forces"? That term seems >not so adequate here. > >I understand that part that are at different distances from the Sun will >have a different gravitational pull, but believe me these differences are >REALLY small. You cannot compare those forces to those which a meteor >experiences when flying close by a planet. > >Tim But the forces are acting on a lever hundreds of thousands of miles long. Thats a lot of torque! Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Wed Nov 6 10:32 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1971" "Wed" "6" "November" "1996" "13:28:59" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "51" "Re: starship-design: Re: Light RamScoop?" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id KAA20535 for starship-design-outgoing; Wed, 6 Nov 1996 10:32:43 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id KAA20507 for ; Wed, 6 Nov 1996 10:32:36 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA11038; Wed, 6 Nov 96 13:32:09 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI010852; Wed Nov 6 13:30:03 1996 Received: by most (4.1/SMI-4.1) id AA10096; Wed, 6 Nov 96 13:29:57 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma010081; Wed Nov 6 13:29:01 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA23496; Wed, 6 Nov 96 13:28:58 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1970 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Re: Light RamScoop? Date: Wed, 6 Nov 1996 13:28:59 -0500 At 7:54 PM 11/6/96, Timothy van der Linden wrote: >To Kelly > >>A thought. Long ago, we were discusing Ramscoops. Eiather for ram fussion >>systems, or ram augmented systems. The later could use interstallar dust >>to augment the reaction mass. At the time we figured that any physical >>scoop would weigh more then the material it scooped up, and ran into papers >>(Heppinhimer wrote one) that suggested that the the drag from a magnetic >>scoop would be greater than the thrust. >> >>What about light scoops? Could we use lasers reflected off of outriding >>light sails? The sails would need to tack back and forth on the beem. But >>could reflect the beam back in toward the line of flight. Pushing material >>inward toward a smaller scoop. This would seem to avoid the drag problem, >>but I've no idea if they would be worth the trouble. > >Where does the laser come from? If it comes from the ship, it will push the >ship back. True, thrust gain from the added scooped mass would have to be greater that the reverse thrust for the system to be practical. >At the moment I can't ask more detailed questions, since I'm not 100% sure >of the configuration. >For example how are you going to "tack the sail back to the ship"? > > >Tim If the mini-sails are ahead of the ship and pointing forward and outward. The mini-sail will reflect the beam inward and forward, and the mini-sail will be pushed outward and forward. If the sail turns back inward. It will reflect the beam outward and backward. The mini-sail pushed inward and forward. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Sun Nov 10 17:43 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1380" "Sun" "10" "November" "1996" "22:44:46" "+0100" "Timothy van der Linden" "TLG.van.der.Linden@tip.nl" nil "33" "starship-design: Re: Light RamScoop?" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id RAA01088 for starship-design-outgoing; Sun, 10 Nov 1996 17:43:32 -0800 (PST) Received: from parijs.tip.nl (parijs.tip.nl [143.177.1.10]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id RAA01071 for ; Sun, 10 Nov 1996 17:43:29 -0800 (PST) Received: from hengelo07.pop.tip.nl by parijs.tip.nl with smtp (Smail3.1.29.1 #16) id m0vMgoa-000DuPC; Sun, 10 Nov 96 21:49 MET X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: X-Sender: t596675@pop1.tip.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1379 From: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Light RamScoop? Date: Sun, 10 Nov 1996 22:44:46 +0100 >>>What about light scoops? Could we use lasers reflected off of outriding >>>light sails? The sails would need to tack back and forth on the beem. But >>>could reflect the beam back in toward the line of flight. Pushing material >>>inward toward a smaller scoop. This would seem to avoid the drag problem, >>>but I've no idea if they would be worth the trouble. >> >>Where does the laser come from? If it comes from the ship, it will push the >>ship back. > >True, thrust gain from the added scooped mass would have to be greater that >the reverse thrust for the system to be practical. > > >>At the moment I can't ask more detailed questions, since I'm not 100% sure >>of the configuration. >>For example how are you going to "tack the sail back to the ship"? > >If the mini-sails are ahead of the ship and pointing forward and outward. >The mini-sail will reflect the beam inward and forward, and the mini-sail >will be pushed outward and forward. If the sail turns back inward. It >will reflect the beam outward and backward. The mini-sail pushed inward >and forward. OK, but how do they get towards the ship again? (instead of only nearer to the path of the ship) I also have doubts about the efficiency, pushing particles over many thousant kilometers, getting them just in front of the ship at the right time seems extremely difficult (if not impossible). Tim From owner-starship-design Mon Nov 11 05:18 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1326" "Mon" "11" "November" "1996" "15:17:46" "+0100" "Timothy van der Linden" "TLG.van.der.Linden@tip.nl" nil "43" "Re: starship-design: Re: Tidal forces" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA11353 for starship-design-outgoing; Mon, 11 Nov 1996 05:18:33 -0800 (PST) Received: from parijs.tip.nl (parijs.tip.nl [143.177.1.10]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA11343 for ; Mon, 11 Nov 1996 05:18:22 -0800 (PST) Received: from hengelo04.pop.tip.nl by parijs.tip.nl with smtp (Smail3.1.29.1 #16) id m0vMwJa-000DlMC; Mon, 11 Nov 96 14:22 MET X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: X-Sender: t596675@pop1.tip.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 1325 From: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: Re: starship-design: Re: Tidal forces Date: Mon, 11 Nov 1996 15:17:46 +0100 Due to mail-deamon error, this message might have arrived before. To Kelly, >>>Tidal forces varry acording to size. Given a structure a dozen times the >>>size of earth (and extrenmly unlikelt situation) it would have larger tidal >>>force. Certainly enough to keep it edge on to the sun. >> >>Why? Can you use a description without using "tidal forces"? That term seems >>not so adequate here. >> >>I understand that part that are at different distances from the Sun will >>have a different gravitational pull, but believe me these differences are >>REALLY small. You cannot compare those forces to those which a meteor >>experiences when flying close by a planet. > >But the forces are acting on a lever hundreds of thousands of miles long. >Thats a lot of torque! Distance Mercury-Sun: 5.79E10 m Mass of the Sun : 1.989E30 kg G=6.67E-11 N m^/kg^2 The gravitational acceleration at distance r is: a=G M/r^2=0.0395734 m/s^2 Now go 100 thousant km further, (1E8 meters) so r=5.79E10+1E8=5.8E10 m which gives a=0.0394371 m/s^2 The difference is da=0.0001363 m/s^2 If my guesses are right, even over a 1E8 meter long lever the force is well below the breakingpoint of steel. The problem is that I don't know how to do an acurate structural analysis, so I can't give you a more clear answer at the moment. Tim From owner-starship-design Mon Nov 11 07:10 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2229" "Mon" "11" "November" "1996" "10:05:49" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "54" "Re: starship-design: Re: Light RamScoop?" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id HAA01157 for starship-design-outgoing; Mon, 11 Nov 1996 07:10:04 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id HAA01050 for ; Mon, 11 Nov 1996 07:09:57 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA19919; Mon, 11 Nov 96 10:09:19 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI019804; Mon Nov 11 10:08:08 1996 Received: by most (4.1/SMI-4.1) id AA08049; Mon, 11 Nov 96 10:08:01 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma007958; Mon Nov 11 10:05:50 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA12143; Mon, 11 Nov 96 10:05:47 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 2228 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Cc: starship-design@lists.uoregon.edu Subject: Re: starship-design: Re: Light RamScoop? Date: Mon, 11 Nov 1996 10:05:49 -0500 At 10:44 PM 11/10/96, Timothy van der Linden wrote: >>>>What about light scoops? Could we use lasers reflected off of outriding >>>>light sails? The sails would need to tack back and forth on the beem. But >>>>could reflect the beam back in toward the line of flight. Pushing material >>>>inward toward a smaller scoop. This would seem to avoid the drag problem, >>>>but I've no idea if they would be worth the trouble. >>> >>>Where does the laser come from? If it comes from the ship, it will push the >>>ship back. >> >>True, thrust gain from the added scooped mass would have to be greater that >>the reverse thrust for the system to be practical. >> >> >>>At the moment I can't ask more detailed questions, since I'm not 100% sure >>>of the configuration. >>>For example how are you going to "tack the sail back to the ship"? >> >>If the mini-sails are ahead of the ship and pointing forward and outward. >>The mini-sail will reflect the beam inward and forward, and the mini-sail >>will be pushed outward and forward. If the sail turns back inward. It >>will reflect the beam outward and backward. The mini-sail pushed inward >>and forward. > >OK, but how do they get towards the ship again? (instead of only nearer to >the path of the ship) They could manuver ahead of the ship and just drift until the ship caught up with them. Assuming they ever needed to get closer to the ship. >I also have doubts about the efficiency, pushing particles over many >thousant kilometers, getting them just in front of the ship at the right >time seems extremely difficult (if not impossible). > >Tim Can't answer that, but I thought this might be doable with a lighter system then a physicalmesh. Say by bringing it closer to the line of flight so that more could be scoped up with a smaller scoop mechanism. Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Mon Nov 11 10:22 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["853" "Mon" "11" "November" "1996" "20:21:44" "+0100" "Timothy van der Linden" "TLG.van.der.Linden@tip.nl" nil "25" "starship-design: Re: Light RamScoop?" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id KAA18905 for starship-design-outgoing; Mon, 11 Nov 1996 10:22:44 -0800 (PST) Received: from parijs.tip.nl (parijs.tip.nl [143.177.1.10]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id KAA18874 for ; Mon, 11 Nov 1996 10:22:39 -0800 (PST) Received: from hengelo16.pop.tip.nl by parijs.tip.nl with smtp (Smail3.1.29.1 #16) id m0vN13i-000DlOC; Mon, 11 Nov 96 19:26 MET X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: X-Sender: t596675@pop1.tip.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 852 From: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Light RamScoop? Date: Mon, 11 Nov 1996 20:21:44 +0100 Kelly wrote: >>OK, but how do they get towards the ship again? (instead of only nearer to >>the path of the ship) > >They could manuver ahead of the ship and just drift until the ship caught >up with them. Assuming they ever needed to get closer to the ship. OK, I had thought of a similar thing, just wondered if you had an other idea :) >>I also have doubts about the efficiency, pushing particles over many >>thousant kilometers, getting them just in front of the ship at the right >>time seems extremely difficult (if not impossible). > >Can't answer that, but I thought this might be doable with a lighter system >then a physicalmesh. Say by bringing it closer to the line of flight so >that more could be scoped up with a smaller scoop mechanism. Lighter it is, the idea is good, but to make it practical more thought is needed. Timothy From owner-starship-design Tue Nov 12 05:09 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7169" "Tue" "12" "November" "1996" "08:07:54" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "154" "starship-design: Solar sails and mission structure" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA00215 for starship-design-outgoing; Tue, 12 Nov 1996 05:09:12 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA00201 for ; Tue, 12 Nov 1996 05:09:08 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA02954; Tue, 12 Nov 96 08:09:08 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI002869; Tue Nov 12 08:08:23 1996 Received: by most (4.1/SMI-4.1) id AA02958; Tue, 12 Nov 96 08:08:20 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma002951; Tue Nov 12 08:07:57 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA22020; Tue, 12 Nov 96 08:07:55 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 7168 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Solar sails and mission structure Date: Tue, 12 Nov 1996 08:07:54 -0500 >Date: Mon, 11 Nov 1996 18:30:29 -0500 >From: Nick Tosh <101765.2200@compuserve.com> >Subject: Solar sails and mission structure >To: "[unknown]" , > "[unknown]" , "[unknown]" , > "[unknown]" , "[unknown]" , > Phillip Bakelaar , > "Kevin C. Houston" , > Zenon Kulpa , > David Levine , > Timothy van der Linden , > "L. Clayton Parker" , > Kelly Starks , > Steve VanDevender > >Hello again everybody. > >Sorry I'm so slow to contribute, but I'm very busy working for my A-levels >- British equivilent of American high school graduation, only harder ;) and >preparing for an admissions interview for Cambridge University (British >equivilent of Harvard, only... no I'm not gonna say that). I'm afraid I'll >be a bit out of phase with everyone else for a while. > >Thanks everyone for the mailing list info, I've just sent my subscription >mail. It doesn't send everything as one big mail does it? It's just that my >family's getting a bit fed up of finding 70 odd mail messages for me every >week! > >Kelly wrote about my solar sail post: > >>The stellar radiation would be too breif and weak to help us much. > >I know it wouldn't be much good for a multimillion ton Asimov, but I had in >mind a light interstellar shuttle to ferry personel and light supplies >between the target star system and Earth, for which a solar sail might >provide helpful additional breaking, especially at highish velocity, maybe >passing the target star completely and reversing back, with the sail furled >of course (and using gravity to help) - see my last mail. (By the way, >Timothy, thanks for telling me that I can either count the photons OR >calculate the Doppler shift. I knew that particle and wave mechanics have >to be kept separate, so I'm not sure why I was being stupid. Always glad to >have you to correct me!) This really links in to my ideas on the mission >structure that I mailed to LIT just before I went off line (must be about a >year ago now). I've dug it out and pasted it below. Is anyone still >interested in mission structure? I don't recall we ever reached a complete >agreement. Please let me know your reactions to this concept. > >Posted: 4 October 1995 > >>I've got a few points to make about the general structure of the mission. >> >> Firstly, the mission should make future journeys to TC more >feasable - this >>would require the setting up of a small but expandable permanent presence >on >>one of the terrestrial planets. The ultimate aim would be for the TC >'colony' >>to be effectively self-supporting. The mistakes of the Appollo program >must be >>avoided - it will be essential to maintain the momentum of the program, >since >>the other alternative would probably be a general loss of intrest and a >set >>back of manned interstellar travel. >> Secondly, I've always felt that using the Asimov to bring the crew >home is an >>inefficient solution. The Asimov is designed to be a heavy exploration >vessel, >>not a ferry. Once it has delivered its huge payload of machinery and >material >>to TC, using it to transport a relatively few number of people back to >Earth is >>somewhat ridiculous. >> I would propose a fairly radical change to the mission plan. >> - The Asimov should be designed as a one way vehicle for >exploration. Its >>effectiveness in this role can be maximized if the return flight is no >longer >>an issue. >> - On arrival in the TC system it would serve as a permanent >space-based >>command, control, and support centre for the develpment projects on the >planet. >>Thus a permanent foothold can be established before planetary construction >is >>even begun. >> - The construction of a 'colony' would be less frantic if those >involved knew >>that there already existed a safe haven for them in-system. >> - Two or more dedicated personnel transport vessels, designed >separately from >>the Asimov, should be constructed. They would only have to ferry people >and >>small quantities of light supplies and equipment, and so would have a tiny >>fraction of the mass of the Asimov. It might therefore be possible to >propel >>this type of vessel using solar sail and magsail technology, augmented by >an >>artificial particle beam during the early phase of the flight, and a small >on >>board antimatter engine for maneuvering and possibly as an early boost. >>Ultimately, a two way particle beam between Earth and TC would be >established. >>It is even possible that the Asimov's engines might be used to produce a >beam >>to increase the acceleration of the small transport vessels back to Earth. >>Cetainly it could provide many support functions for the transports (eg >>communication relay, TC based mission control, repair). >> - These vessels would be used to relieve the crew of the Asimov >with fresh >>people. The round trip (time dilated) for the original crew might be 25-30 >>years (some might want to stay longer). With two vessels, a relief ship >might >>arrive in TC every 15 years (TC time) >> >> If a permanent presence is to be established, it is clear that an >>interstellar shuttle system is needed. Further, it is obvious that a >>prohibitively expensive Asimov type vessel it not appropriate for this >>function. I conclude that if an austere ferry system will have to be built >>eventually, it makes sense to incorporate it into the original mission. >The >>advantages of having the huge Asimov remaining as a planet-orbiting base >in TC >>are obvious. >> >>Please respond with any opinions you might have about what I've said. Do >you >>agree with my basic argument, if not the details? > >On another topic, I'm still not happy with the stellar drive system. It >still seems to me (after reading everyone's mails on the subject) that for >it to obey Newton's Third Law, it depends on a particular distribution of >charge around the drive that may (or may not, for all I know, I haven't >looked at this thoroughly) be statistically very probable, but surely isn't >an absolute requirement. So I ask again: does this concept put conservation >of momentum on an equal footing as the laws of thermodynamics (which are >essentially statistical, not absolute)? If it does, either it's very wrong, >or I'll be very, very, unhappy. > >Sorry I haven't responded as fully as I'd like to other people's mails, but >I am reading them and keeping fairly up to date. > ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Tue Nov 12 05:47 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9685" "Tue" "12" "November" "1996" "08:44:37" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "199" "starship-design: Re: Solar sails and mission structure" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id FAA12476 for starship-design-outgoing; Tue, 12 Nov 1996 05:47:56 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id FAA12464 for ; Tue, 12 Nov 1996 05:47:51 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05696; Tue, 12 Nov 96 08:47:39 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI005570; Tue Nov 12 08:45:35 1996 Received: by most (4.1/SMI-4.1) id AA03851; Tue, 12 Nov 96 08:45:28 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma003833; Tue Nov 12 08:44:41 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA28326; Tue, 12 Nov 96 08:44:39 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 9684 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: Nick Tosh <101765.2200@compuserve.com> Cc: starship-design@lists.uoregon.edu Subject: starship-design: Re: Solar sails and mission structure Date: Tue, 12 Nov 1996 08:44:37 -0500 At 6:30 PM 11/11/96, Nick Tosh wrote: >Hello again everybody. Hi Nick! Welcome back. I forwarded your post to the starship design mailing list. Oh, have you seen the new draft sites at: http://165.254.130.90/LIT/ or http://www.urly-bird.com/LIT/ ? >Sorry I'm so slow to contribute, but I'm very busy working for my A-levels >- British equivilent of American high school graduation, only harder ;) and >preparing for an admissions interview for Cambridge University (British >equivilent of Harvard, only... no I'm not gonna say that). I'm afraid I'll >be a bit out of phase with everyone else for a while. Good luck. >Thanks everyone for the mailing list info, I've just sent my subscription >mail. It doesn't send everything as one big mail does it? It's just that my >family's getting a bit fed up of finding 70 odd mail messages for me every >week! No it sends then one at a time. We're not generally posting as much as we used to. >Kelly wrote about my solar sail post: > >>The stellar radiation would be too breif and weak to help us much. > >I know it wouldn't be much good for a multimillion ton Asimov, but I had in >mind a light interstellar shuttle to ferry personel and light supplies >between the target star system and Earth, for which a solar sail might >provide helpful additional breaking, especially at highish velocity, maybe >passing the target star completely and reversing back, with the sail furled >of course (and using gravity to help) - see my last mail. (By the way, >Timothy, thanks for telling me that I can either count the photons OR >calculate the Doppler shift. I knew that particle and wave mechanics have >to be kept separate, so I'm not sure why I was being stupid. Always glad to >have you to correct me!) This really links in to my ideas on the mission >structure that I mailed to LIT just before I went off line (must be about a >year ago now). I've dug it out and pasted it below. Is anyone still >interested in mission structure? I don't recall we ever reached a complete >agreement. Please let me know your reactions to this concept. Solar energy is very weak. Even huge sails on light weight ships, only get low acceleration very deep in the solar system. For a starship you need very high acceleration, for long distences. Even if the solar sail had virtually no cargo it couldn't do interstellar well. >Posted: 4 October 1995 > >>I've got a few points to make about the general structure of the mission. >> >> Firstly, the mission should make future journeys to TC more >> feasable - this would require the setting up of a small but expandable >> permanent presence on one of the terrestrial planets. The ultimate >> aim would be for the TC 'colony' to be effectively self-supporting. >> The mistakes of the Apollo program must be avoided - it will be >> essential to maintain the momentum of the program, since the other >> alternative would probably be a general loss of intrest and a set >> back of manned interstellar travel. This presuposes you want and can afford a colony there. Given one would be very expensive to maintain (all those long supply flights), its unlikely to be maintained. Be self sufficent would require a huge population and investment in equipment. Which seems unwarrented. We also haven't identified a reason to colonize there. If you did want to colonize their you wouldn't want to go to the planets. Its harder to find and process raw materials their, and since you can't use the biosphere anyway, build a space colony. Apollos problem wasn't that it lost momentum, it was that it had completed its goals. Apollo was a race. We won, But after a race, you don't keep going around the track over and over. >> Secondly, I've always felt that using the Asimov to bring the >> crew home is an inefficient solution. The Asimov is designed to be >> a heavy exploration vessel, not a ferry. Once it has delivered its >> huge payload of machinery and material to TC, using it to transport >> a relatively few number of people back to Earth is somewhat ridiculous. >> I would propose a fairly radical change to the mission plan. >> - The Asimov should be designed as a one way vehicle for >> exploration. Its effectiveness in this role can be maximized if >> the return flight is no longer an issue. >> - On arrival in the TC system it would serve as a permanent >> space-based command, control, and support centre for the develpment >> projects on the planet. Thus a permanent foothold can be established >> before planetary construction is even begun. >> - The construction of a 'colony' would be less frantic if >> those involved knew that there already existed a safe haven for >> them in-system. >> - Two or more dedicated personnel transport vessels, designed >> separately from the Asimov, should be constructed. They would only >> have to ferry people and small quantities of light supplies and >> equipment, and so would have a tiny fraction of the mass of the >> Asimov. It might therefore be possible to propel this type of >> vessel using solar sail and magsail technology, augmented by an >> artificial particle beam during the early phase of the flight, and >> a small on board antimatter engine for maneuvering and possibly >> as an early boost. Ultimately, a two way particle beam between >> Earth and TC would be established. It is even possible that the >> Asimov's engines might be used to produce a beam to increase the >> acceleration of the small transport vessels back to Earth. Cetainly >> it could provide many support functions for the transports (eg >> communication relay, TC based mission control, repair). >> - These vessels would be used to relieve the crew of the >> Asimov with fresh people. The round trip (time dilated) for the >> original crew might be 25-30 years (some might want to stay longer). >> With two vessels, a relief ship might arrive in TC every 15 years >> (TC time) >> >> If a permanent presence is to be established, it is clear that an >>interstellar shuttle system is needed. Further, it is obvious that a >>prohibitively expensive Asimov type vessel it not appropriate for this >>function. I conclude that if an austere ferry system will have to be built >>eventually, it makes sense to incorporate it into the original mission. >> The advantages of having the huge Asimov remaining as a planet-orbiting >> base in TC are obvious. >> >> Please respond with any opinions you might have about what I've said. >> Do you agree with my basic argument, if not the details? The idea of a big construction ship sent out once to set up catcher facilities for later faster sail craft has been tossed about. (We were leaning toward microwave sail vs partical beam thou.) But the leaving the main ship there might not make a lot of sence. The ship is largely huge fuel reserves and engines with habitation and equipment added on. You could build a colony platform and park most of the equipment on that. Or even build stations near each of the more interesting areas/planets in the system, and disperse equipment amoung them. However since you need the hab deck systems and suplies to get back, and probably need the engines, you might as well take the striped down main ship back. The exception of course would be if you had built catcher facilities for faster follow on ships (interstellar shuttles?). In that case it may or may no make more sence (and be quicker) to leave the ship and take a fast shuttle home. >On another topic, I'm still not happy with the stellar drive system. It >still seems to me (after reading everyone's mails on the subject) that for >it to obey Newton's Third Law, it depends on a particular distribution of >charge around the drive that may (or may not, for all I know, I haven't >looked at this thoroughly) be statistically very probable, but surely isn't >an absolute requirement. So I ask again: does this concept put conservation >of momentum on an equal footing as the laws of thermodynamics (which are >essentially statistical, not absolute)? If it does, either it's very wrong, >or I'll be very, very, unhappy. > >Sorry I haven't responded as fully as I'd like to other people's mails, but >I am reading them and keeping fairly up to date. I'm not sure what drive system your talking about? The three we are mainly discusing now are: The Explorer classes pure fusion rockets, with acceleration fuel laser launched to it as it leaves Sol. (Top cruse speed 1/3rd C ?) The Fuel/sail Class, where the deceleration fuel (Lithium-6) is spreed out into a big microwave sail. The ship is accelerated out of our system via microwaves. The contracts the sail, and burns it in fusion motors to decelerate into the target starsystem. MARS, which uses a microwave sail to accelerat away from earth, and then uses the microwave beam to power deceleration rockets on entering the system. Also Argosey/tradwinds was discused before its advocate droped off line (or sent us a copy of the web page for it!). It used microwave shuttle craft between the stars, AFTER a predicesor ship set up the microwave transmitter platforms in the target starsystem. Kelly P.S. I moveing to a new city next week, so I may be offline for a while. ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Tue Nov 12 09:23 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["325" "Tue" "12" "November" "1996" "12:28:19" "-0500" "David Levine" "David@interworld.com" nil "15" "starship-design: IP change" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id JAA14589 for starship-design-outgoing; Tue, 12 Nov 1996 09:23:11 -0800 (PST) Received: from www1.interworld.com (www.InterWorld.Com [165.254.130.4]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id JAA14563 for ; Tue, 12 Nov 1996 09:23:09 -0800 (PST) Received: by www1.interworld.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.993.5) id <01BBD094.FD185C70@www1.interworld.com>; Tue, 12 Nov 1996 12:28:20 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.993.5 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: David Levine Content-Type: text/plain; charset="us-ascii" Content-Length: 324 From: David Levine Sender: owner-starship-design To: "'starship-design@lists.uoregon.edu'" Subject: starship-design: IP change Date: Tue, 12 Nov 1996 12:28:19 -0500 Just a minor IP change: My site is now 165.254.130.50 instead of 165.254.130.90 Sorry for any inconvenience! Kelly, I have the list of changes - I will do them... hopefully soon. David ------------------ David Levine InterWorld Technology Ventures, Inc. "A stroke of the brush does not guarantee art from the bristles." From owner-starship-design Tue Nov 12 10:42 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1266" "Tue" "12" "November" "1996" "13:40:26" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "44" "Re: starship-design: IP change" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id KAA23626 for starship-design-outgoing; Tue, 12 Nov 1996 10:42:49 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id KAA23579 for ; Tue, 12 Nov 1996 10:42:38 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA07062; Tue, 12 Nov 96 13:42:19 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI007002; Tue Nov 12 13:41:26 1996 Received: by most (4.1/SMI-4.1) id AA10574; Tue, 12 Nov 96 13:41:21 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma010566; Tue Nov 12 13:40:30 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA29910; Tue, 12 Nov 96 13:40:28 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1265 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: David Levine Cc: "'starship-design@lists.uoregon.edu'" Subject: Re: starship-design: IP change Date: Tue, 12 Nov 1996 13:40:26 -0500 At 12:28 PM 11/12/96, David Levine wrote: >Just a minor IP change: >My site is now 165.254.130.50 >instead of 165.254.130.90 > >Sorry for any inconvenience! I tried the new address, but got no responce. Are you sure thats the correct address. > >Kelly, I have the list of changes - I will do them... hopefully soon. > >David Ok, good. (I could point out youve said that a few other times over the last several months.) Oh, could you upload all the newletters to your site? I was going to try to make a new newsletter table of contents, but I don't have anything to test it on, and I'm not sure what the names are of the sections that can't be accessed (part of the Sunsite Newsleter TOC is crashed.). Kelly >------------------ >David Levine >InterWorld Technology Ventures, Inc. >"A stroke of the brush does not guarantee art from the bristles." ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Wed Nov 13 06:53 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1631" "Wed" "13" "November" "1996" "09:49:09" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "40" "starship-design: NASA smells a warp drive?" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id GAA01868 for starship-design-outgoing; Wed, 13 Nov 1996 06:53:34 -0800 (PST) Received: from most.fw.hac.com (gw1.hughes-defense-comm.com [151.168.2.3]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id GAA01853 for ; Wed, 13 Nov 1996 06:53:31 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA16282; Wed, 13 Nov 96 09:52:47 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI016016; Wed Nov 13 09:49:59 1996 Received: by most (4.1/SMI-4.1) id AA07275; Wed, 13 Nov 96 09:49:55 EST Received: from ss2.fw.hac.com(151.168.145.200) by most via smap (V1.5khhunt) id sma007255; Wed Nov 13 09:49:09 1996 Received: from [151.168.146.187] (kgstar) by ss2.uiv (4.1/SMI-4.1) id AA11235; Wed, 13 Nov 96 09:49:06 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Content-Type: text/plain; charset="us-ascii" Content-Length: 1630 From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: NASA smells a warp drive? Date: Wed, 13 Nov 1996 09:49:09 -0500 News Flash. Someone I correspond with in NASA is part of a "Breakthrough Propulsion phusics Research Program". He sent me a copy of a paper they're going to present at their conference in January. (Sorry I was asked not to widely distribute it until after then.) They are working to coordinate research into new theories and phenomena that have recently emerged in scientific literature and laboratory results. They think some of these might point toward possibilities for exotic drive systems such as: - Eliminating or dramatically reducing the need for rocket propellant by the manipulation of inertia, gravity, or other matter, fields, spacetime interactions. - Ultra high speed space travel. Possibly through induced motion of spacetime itself. Possibly at hyper-light speeds. - Power production systems that might allow us to tap into vacume fluctuation energy. These are ideas they feel show promise due to emerging theories and experimental results which point to exotic possibilities. To put it mildly, I was a little suprized to see a paper from a group at NASA. Suggesting ways to facilitate the development of anti-grav, warpdrive, inertia altering, and zero point energy taping systems!! Kelly ---------------------------------------------------------------------- Kelly Starks Phone: (219) 429-7066 Fax: (219) 429-6859 Sr. Systems Engineer Mail Stop: 10-39 Hughes defense Communications 1010 Production Road, Fort Wayne, IN 46808-4106 Email: kgstar@most.fw.hac.com ---------------------------------------------------------------------- From owner-starship-design Sat Nov 16 14:44 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1370" "Sat" "16" "November" "1996" "17:44:35" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "40" "Re: starship-design: NASA smells a warp drive?" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.7.6/8.7.3) id OAA11756 for starship-design-outgoing; Sat, 16 Nov 1996 14:44:47 -0800 (PST) Received: from emout15.mail.aol.com (emout15.mx.aol.com [198.81.11.41]) by darkwing.uoregon.edu (8.7.6/8.7.3) with SMTP id OAA11702 for ; Sat, 16 Nov 1996 14:44:44 -0800 (PST) Received: by emout15.mail.aol.com (8.6.12/8.6.12) id RAA09643; Sat, 16 Nov 1996 17:44:35 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961116174434_1715862904@emout15.mail.aol.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: KellySt@aol.com Content-Type: text Content-Length: 1369 From: KellySt@aol.com Sender: owner-starship-design To: TLG.van.der.Linden@tip.nl, starship-design@lists.uoregon.edu Subject: Re: starship-design: NASA smells a warp drive? Date: Sat, 16 Nov 1996 17:44:35 -0500 >> I had been hearing bits and peices of this stuff for >> the last couple of years. A physic paper here, a tech >> journal bit there. But this is the first time anyone >> was seriuosly trying to focus this stuff toward a goal. >> Namely space travel. > >> Hope some of it pans out. Certainly could change the >> nature of our tech arguments. > Inertia inhibiters and cut the fuel ration by a >>factor of 40....> ;) > Or it may be as exotic as generating anti-matter? Or as trivial as generating a laser beam. Who can tell? > Assuming that the basic conservation law of energy > is not broken, we still need a lot of energy. If for > example we would know how to make a wormhole, > then the question would remain if we had enough > energy and power to really do it. > In that case the mass ratios would be similar to > my anti-matter numbers. You might ned a lot of energy, but it could be wildly different from the anti matter ones, or it could violate our curent understanding of the basic conservation law of energy. Weirder things have happened. > Only the following two would be a help: > -Induced motion of spacetime itself > -To tap into vacume fluctuation energy > but they would render all conservation laws useless. Or innertia suppresion could eliminate most of the energy need to accelerate an object. Kelly Tim From owner-starship-design Tue Nov 26 05:47 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5628" "Tue" "26" "November" "1996" "15:49:27" "+0100" "Timothy van der Linden" "TLG.van.der.Linden@tip.nl" nil "110" "starship-design: PV and laser" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id FAA02794 for starship-design-outgoing; Tue, 26 Nov 1996 05:47:28 -0800 (PST) Received: from parijs.tip.nl (parijs.tip.nl [143.177.1.10]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id FAA02784 for ; Tue, 26 Nov 1996 05:47:23 -0800 (PST) Received: from hengelo04.pop.tip.nl by parijs.tip.nl with smtp (Smail3.1.29.1 #16) id m0vSNz8-000DmBC; Tue, 26 Nov 96 14:55 MET X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: X-Sender: t596675@pop1.tip.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 5627 From: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: PV and laser Date: Tue, 26 Nov 1996 15:49:27 +0100 Hi all, this may develop just in time to use around 2040. It may make beaming much cheaper and easier. It can also be found on the Web: http://www.sciam.com/1296issue/1296techbus4.html (From there you can also find another link) Scientific American: Technology and Business CHEMICAL ENGINEERING PLASTIC POWER Polymers take a step forward as photovoltaic cells and lasers For nearly 20 years, scientists have expected great things from semiconducting polymers--chimerical chemicals that can be as pliable as plastic wrap and as conductive as copper wiring. Indeed, these organic compounds have conjured dreams of novel optoelectronic devices, ranging from transparent transistors to flexible light-emitting diodes. Few of these ideas have made it out of the laboratory. But in the past year, researchers have added two promising candidates to the wish list: solar cells and solid-state lasers. The lasting appeal of these materials--also called synthetic metals--is that they are more durable and less expensive than their inorganic doubles. Furthermore, they are easy to make. Like all plastics, they are long, carbon-based chains strung from simple repeating units called monomers. To make them conductive, they need only be doped with atoms that donate negative or positive charges to each unit. These charges clear a path through the chain for traveling currents. Scientists at Advanced Research Development in Athol, Mass., have made plastic solar cells using two different polymers, polyvinyl alcohol (PVA) and polyacetylene (PA). Films of this copolymer, patented as Lumeloid, polarize light and, in theory at least, change nearly three quarters of it into electricity--a remarkable gain over the 20 percent maximum conversion rate predicted for present-day photovoltaic cells. Lumeloid also promises to be cheaper and safer. Alvin M. Marks, inventor and company president, estimates that whereas solar cells now cost some $3 to $4 per watt of electricity produced, Lumeloid will not exceed 50 cents. The process by which these films work resembles photosynthesis, Marks explains. Plants rely on diode structures in their leaves, called diads, that act as positive and negative terminals and channel electrons energized by sunlight. Similarly, Lumeloid contains molecular diads. Electrodes extract current from the film's surface. To go the next step, Marks is developing a complementary polymer capable of storing electricity. "If photovoltaics are going to be competitive, they must work day and night," he adds. His two-film package, to be sold in a roll like tinfoil, would allow just that. Plastics that swap electricity for laser light are less well developed, but progress is coming fast. Only four years ago Daniel Moses of the University of California at Santa Barbara announced that semiconducting polymers in a dilute solution could produce laser light, characterized by a coherent beam of photons emitted at a single wavelength. This past July, at a conference in Snowbird, Utah, three research teams presented results showing that newer polymer solids could do the same. "I'm a physicist. I can't do anything with my hands," says Z. Valy Vardeny of the University of Utah, who chaired the meeting. "But the chemists who have created these new materials are geniuses." Earlier generations of semiconducting polymers could not lase for two main reasons. First, when bombarded with electricity or photons, they would convert most of that energy into heat instead of light--a problem called poor luminescence efficiency. Second, the films usually absorbed the photons that were produced, rather than emitting them, so that the polymers lacked optical gain--a measure of a laser medium's ability to snowball photons into an intense pulse. Because the newer materials have fewer impurities, they offer much higher luminescence efficiencies and show greater lasing potential, Vardeny states. In the Japanese Journal of Applied Physics, his group described a derivative of poly (p-phenylenevinylene), or PPV, with a luminescence efficiency of 25 percent. The red light was composed of photons having the same wavelength, but it did not travel in a single beam. In Nature, another group from the Snowbird meeting offered a way around this shortcoming. Richard H. Friend and his colleagues at the University of Cambridge placed a PPV film inside a device called a microcavity. Mirrors in the structure bounced the emitted light back and forth, amplifying it into a focused laser beam. The third group from Snowbird, led by Alan J. Heeger of U.C.S.B., tested more than a dozen polymers and blends as well. Their results, which appeared in the September 27 issue of Science, show that these materials can emit laserlike light across the full visible spectrum--even in such rare laser hues as blue and green. In place of a microcavity, Heeger set up his samples so that the surrounding air confined the emitted photons to the polymer, where they could stimulate further emissions. "We wanted to show that a whole class of materials do this and that they definitely provide optical gain," Heeger says. The challenge now will be finding a way to power these polymers electrically. All three groups energized their samples using another laser, but practical devices will need to run off current delivered from electrodes. It is no small problem. Vardeny notes that electrical charges generate destructive levels of heat and that electrodes can react chemically with the film, lowering the polymer's luminescence efficiency. "It's going to be hard," Heeger concurs, "but I'm optimistic." --Kristin Leutwyler From owner-starship-design Fri Nov 29 13:37 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["700" "Fri" "29" "November" "1996" "16:40:17" "-0500" "DotarSojat@aol.com" "DotarSojat@aol.com" nil "21" "starship-design: Re: Twin paradox" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id NAA03762 for starship-design-outgoing; Fri, 29 Nov 1996 13:37:46 -0800 (PST) Received: from emout16.mail.aol.com (emout16.mx.aol.com [198.81.11.42]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id NAA03749 for ; Fri, 29 Nov 1996 13:37:43 -0800 (PST) Received: by emout16.mail.aol.com (8.6.12/8.6.12) id QAA29553; Fri, 29 Nov 1996 16:40:17 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961129164017_1784709121@emout16.mail.aol.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: DotarSojat@aol.com Content-Type: text Content-Length: 699 From: DotarSojat@aol.com Sender: owner-starship-design To: 101765.2200@compuserve.com cc: starship-design@lists.uoregon.edu Subject: starship-design: Re: Twin paradox Date: Fri, 29 Nov 1996 16:40:17 -0500 Hi Nick Twin Paradox? There really isn't any. All you have to do to dispel the notion that there is a "paradox" is to ask: What does each twin see when he looks out his window during the "trip?" The one who sees the UNIVERSE "moving" will be the younger at the end of the trip. I discuss the issue of the twin "paradox," for both uniform and accelerated motion, at some length in my Paper "An Engineering Review of Relativity for Interstellar Flight." I have success- fully sent copies of this Paper via email to Timothy and Steve. Rex (Rex Finke) P.S. I, too, feel that a manned mission to a star should be for colonisation, not just for a probe. (To Mars, also.) From owner-starship-design Fri Nov 29 20:30 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1303" "Fri" "29" "November" "1996" "20:33:17" "-0800" "Steve VanDevender" "stevev@efn.org" nil "30" "starship-design: Re: Twin paradox" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id UAA28758 for starship-design-outgoing; Fri, 29 Nov 1996 20:30:35 -0800 (PST) Received: from haus.efn.org (haus.efn.org [198.68.17.3]) by darkwing.uoregon.edu (8.8.3/8.8.3) with ESMTP id UAA28744 for ; Fri, 29 Nov 1996 20:30:31 -0800 (PST) Received: from tzadkiel.efn.org (stevev@cisco-ts10-line12.uoregon.edu [128.223.150.110]) by haus.efn.org (8.8.3/8.7.3) with ESMTP id UAA09383; Fri, 29 Nov 1996 20:36:39 -0800 (PST) Received: (from stevev@localhost) by tzadkiel.efn.org (8.8.3/8.8.3) id UAA21152; Fri, 29 Nov 1996 20:33:17 -0800 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199611300433.UAA21152@tzadkiel.efn.org> In-Reply-To: <961129164017_1784709121@emout16.mail.aol.com> References: <961129164017_1784709121@emout16.mail.aol.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Steve VanDevender Content-Type: text Content-Length: 1302 From: Steve VanDevender Sender: owner-starship-design To: starship-design@lists.uoregon.edu Cc: 101765.2200@compuserve.com Subject: starship-design: Re: Twin paradox Date: Fri, 29 Nov 1996 20:33:17 -0800 DotarSojat@aol.com writes: > Hi Nick > > Twin Paradox? There really isn't any. > > All you have to do to dispel the notion that there is a "paradox" > is to ask: What does each twin see when he looks out his window > during the "trip?" The one who sees the UNIVERSE "moving" will be > the younger at the end of the trip. However, the Twin non-Paradox would still happen even if one twin stayed on a fast-moving spaceship while the other took a relativistic jaunt in the ship's shuttlecraft; the one who left and came back on the shuttlecraft would be younger. The critical issue is acceleration, not apparent motion of the Universe. The twin in the rocket experiences acceleration, because in order to make a round trip he must accelerate, turn around, and accelerate back, and this is the fundamental asymmetry, because the stay-at-home twin does not experience a change in acceleration. Once can even construct a similar "paradox" where both twins take round-trips with different accelerations; the twin who experiences the greater self-measured acceleration will be younger when they meet again. At the risk of repeating an often-repeated suggestion again, get _Spacetime Physics_ by Taylor and Wheeler, which has a simple, clear explanation of the Twin Paradox and its resolution. From owner-starship-design Sat Nov 30 01:26 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["454" "Sat" "30" "November" "1996" "04:31:06" "EST" "Steve Revilak" "revilak@umbsky.cc.umb.edu" nil "14" "starship-design: re: Twin Paradox" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id BAA23095 for starship-design-outgoing; Sat, 30 Nov 1996 01:26:19 -0800 (PST) Received: from gemini.cc.umb.edu (gemini.cc.umb.edu [158.121.2.2]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id BAA23041 for ; Sat, 30 Nov 1996 01:26:16 -0800 (PST) Received: by umbsky.cc.umb.edu (MX V4.2 VAX) id 285; Sat, 30 Nov 1996 04:31:06 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <009AC1FF.C3FB7960.285@umbsky.cc.umb.edu> Errors-To: owner-starship-design@LISTS.UOREGON.EDU Precedence: bulk Reply-To: Steve Revilak Content-Type: text Content-Length: 453 From: Steve Revilak Sender: owner-starship-design To: STARSHIP-DESIGN@LISTS.UOREGON.EDU Subject: starship-design: re: Twin Paradox Date: Sat, 30 Nov 1996 04:31:06 EST /However, the Twin non-Paradox would still happen even if one twin stayed /on a fast-moving spaceship while the other took a relativistic jaunt in /the ship's shuttlecraft; the one who left and came back on the /shuttlecraft would be younger. Could you point me toward a little more info on this phenomenon? Are we referring to biological twins, or 'twins' as in equivalent beings coexisting in parallel universes? Steve revilak@umbsky.cc.umb.edu From owner-starship-design Sat Nov 30 01:43 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1578" "Sat" "30" "November" "1996" "01:47:18" "-0800" "Steve VanDevender" "stevev@efn.org" nil "30" "starship-design: re: Twin Paradox" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id BAA24519 for starship-design-outgoing; Sat, 30 Nov 1996 01:43:12 -0800 (PST) Received: from haus.efn.org (haus.efn.org [198.68.17.3]) by darkwing.uoregon.edu (8.8.3/8.8.3) with ESMTP id BAA24510 for ; Sat, 30 Nov 1996 01:43:09 -0800 (PST) Received: from tzadkiel.efn.org (stevev@cisco-ts6-line13.uoregon.edu [128.223.150.43]) by haus.efn.org (8.8.3/8.7.3) with ESMTP id BAA25199; Sat, 30 Nov 1996 01:50:39 -0800 (PST) Received: (from stevev@localhost) by tzadkiel.efn.org (8.8.3/8.8.3) id BAA22233; Sat, 30 Nov 1996 01:47:18 -0800 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199611300947.BAA22233@tzadkiel.efn.org> In-Reply-To: <009AC1FF.C3FB7960.285@umbsky.cc.umb.edu> References: <009AC1FF.C3FB7960.285@umbsky.cc.umb.edu> Errors-To: owner-starship-design@LISTS.UOREGON.EDU Precedence: bulk Reply-To: Steve VanDevender Content-Type: text Content-Length: 1577 From: Steve VanDevender Sender: owner-starship-design To: Steve Revilak Cc: STARSHIP-DESIGN@LISTS.UOREGON.EDU Subject: starship-design: re: Twin Paradox Date: Sat, 30 Nov 1996 01:47:18 -0800 Steve Revilak writes: > /However, the Twin non-Paradox would still happen even if one twin stayed > /on a fast-moving spaceship while the other took a relativistic jaunt in > /the ship's shuttlecraft; the one who left and came back on the > /shuttlecraft would be younger. > > Could you point me toward a little more info on this phenomenon? > Are we referring to biological twins, or 'twins' as in equivalent beings > coexisting in parallel universes? The so-called "Twin Paradox" refers to a thought-experiment in relativistic physics where one of a pair of biological twins takes a trip in a starship at relativistic speeds while the other remains on Earth. Biological twins were chosen simply because they are the same age at the start of the trip. The traveling twin, on his return, has aged less than the twin who stayed at home because of relativistic effects. Usually the paradox is posed with the misleading implication that the situations of the two twins are symmetrical, but the paradox is resolved by showing that the traveling twin, who had to accelerate and decelerate during his trip, therefore took a different path through spacetime and experienced a different amount of elapsed time. Since this mailing list is for discussion of space travel methods that are compatible with existing laws of physics, we tend not to talk about parallel universes, warp drives, and other fanciful but unlikely things. My posting that you replied to contained a reference to an introductory text on relativistic physics that covers the Twin Paradox in detail. From owner-starship-design Sat Nov 30 11:56 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["530" "Sat" "30" "November" "1996" "15:01:08" "EST" "Steve Revilak" "revilak@umbsky.cc.umb.edu" nil "16" "starship-design: re: twin paradox" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id LAA15909 for starship-design-outgoing; Sat, 30 Nov 1996 11:56:10 -0800 (PST) Received: from gemini.cc.umb.edu (gemini.cc.umb.edu [158.121.2.2]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id LAA15899 for ; Sat, 30 Nov 1996 11:56:07 -0800 (PST) Received: by umbsky.cc.umb.edu (MX V4.2 VAX) id 380; Sat, 30 Nov 1996 15:01:09 EST X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <009AC257.C7E5A3E0.380@umbsky.cc.umb.edu> Errors-To: owner-starship-design@LISTS.UOREGON.EDU Precedence: bulk Reply-To: Steve Revilak Content-Type: text Content-Length: 529 From: Steve Revilak Sender: owner-starship-design To: STARSHIP-DESIGN@LISTS.UOREGON.EDU Subject: starship-design: re: twin paradox Date: Sat, 30 Nov 1996 15:01:08 EST /Since this mailing list is for discussion of space travel methods that /are compatible with existing laws of physics, we tend not to talk about /parallel universes, warp drives, and other fanciful but unlikely /things. / /My posting that you replied to contained a reference to an introductory /text on relativistic physics that covers the Twin Paradox in detail. Steve-- Thanks for the info, and pardon my air of newbie-ism on the list. I have read of this in fact. SUrprise, surprise... Steve Revilak@Umbsky.cc.umb.edu From owner-starship-design Sat Nov 30 12:24 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4778" "Sat" "30" "November" "1996" "15:27:32" "-0500" "Nick Tosh" "101765.2200@compuserve.com" nil "81" "starship-design: Mission Structure" "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id MAA27163 for starship-design-outgoing; Sat, 30 Nov 1996 12:24:56 -0800 (PST) Received: from arl-img-7.compuserve.com (arl-img-7.compuserve.com [149.174.217.137]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id MAA27154 for ; Sat, 30 Nov 1996 12:24:54 -0800 (PST) Received: by arl-img-7.compuserve.com (8.6.10/5.950515) id PAA07752; Sat, 30 Nov 1996 15:27:40 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <199611301527_MC1-C88-7A04@compuserve.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Nick Tosh <101765.2200@compuserve.com> Content-Type: text Content-Length: 4777 From: Nick Tosh <101765.2200@compuserve.com> Sender: owner-starship-design To: SD Subject: starship-design: Mission Structure Date: Sat, 30 Nov 1996 15:27:32 -0500 Hi everyone. Kelly wrote: >This presuposes you want and can afford a colony there. Given one would be >very expensive to maintain (all those long supply flights), its unlikely to >be maintained. Be self sufficent would require a huge population and >investment in equipment. Which seems unwarrented. We also haven't >identified a reason to colonize there. >If you did want to colonize their you wouldn't want to go to the planets. >Its harder to find and process raw materials their, and since you can't use >the biosphere anyway, build a space colony. What's the point of a hugely expensive manned trip there and back? With advances in computer and robot technology, probes could surely perform this task at much reduced cost, and with a powerful communication laser / maser, wouldn't even need to make the return journey. The only motive for a manned flight would be an extended stay and a very thorough on-site inspection of the planets / stellar system. If this is to be done, I don't see that a permanent presence would be so much more difficult or expensive. Compared to the cost of shifting many millions of tons from Earth to TC within a few years, the cost of maintaining a presence in-system can't be all that astronomical. You wouldn't need a continuous flow if supply flights. Food and supplies would be taken on the initial flight, and a major component of the mission would be to set up a self sustaining biosystem, either on a planet or in space (I feel that a planet, despite the disadvantages of the gravity well, would have such psychological advantages that it should not be dismissed lightly). Biotechnology is one of the most rapidly advancing areas of knowledge right now. I think we can be fairly confident that within a hundred years or so 'designer' organisms could be created specifically for colinization purposed. A pathfinder probe sent before the main mission to gather data on the planet(s) might make it possible for plants to be engineered to survive in the 'open,' which would make planet-bound base easier to set up - space would not have to be made within the base for food crops (of course, plants/algae for oxygen generation would still have to kept within the base. For maximum efficiency, I would envisage separate, specisialist organisms designed for the two main purposes of food and O2). The other relevant technology, also undergoing rapid advancement at present, is virtual reality. The psychological impact of spending long periods of time - perhaps an entire lifetime - away from Earth would be diminished, perhaps eliminated, by the availability of highly realistic VR systems, possibly indistinguishable from reality. Updates could be sent regularly from Earth to keep the simulations up-to date. TC could be kept no more than 10 years (or whatever the Earth-TC light distance is) behind Earth in this way. The idea of replacing reality with simulations might seem a horifc idea to us, but we must bear in mind the social and collective psychological changes that may well occur in our culture as VR is developed. I can imagine the distinction between reality and simulation that seems so important to us being much less of an issue in a generation or two (of course, colonists would still spend most of their time in the 'real' world doing scientific research and construction work.) We must therefore consider the possibility that getting home might not be a major issue for the colonists - or at least that people for whom this would be true could be chosen for the mission. A large enough gene pool for a self-sustaining colony could perhaps be squeezed into the Asimov (are we still calling it this?), as long as careful genetic screening was carried out to ensure that those chosen did not unnecessarily duplicate gene types. Even if this were not possible, one way flights of small ships just carrying colonists (no exploration equipment) could be sent to top up the gene pool. The cost of this would be reduced if the first wave of colonists had time to set up a decleerating particle beam / maser first (this would also enable return flights, if absolutely essential). I really believe that some kind of colonisation is required to justify a manned mission of the scale we have been considering. The only benefit that, in my opinion, could possibly outweight the almost globally crippling cost of the program would be a major social advancement of humanity (a two starsystem culture - I have thought of many advantages of such a culture which I won't go into here). A colonization mission would add so much to the return from the massive investment, for a proportional increase in cost which, for a culture presumably with colonization experience within the solar system, would not be excessive. Nick Tosh From owner-starship-design Sat Nov 30 14:42 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["123" "Sat" "30" "November" "1996" "17:44:04" "-0500" "Phil Bakelaar" "pbakelaar@exit109.com" nil "7" "starship-design: changing email..." "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id OAA05992 for starship-design-outgoing; Sat, 30 Nov 1996 14:42:14 -0800 (PST) Received: from hiway1.exit109.com (root@hiway1.exit109.com [205.164.176.32]) by darkwing.uoregon.edu (8.8.3/8.8.3) with ESMTP id OAA05962 for ; Sat, 30 Nov 1996 14:42:11 -0800 (PST) Received: from pbakelaar.exit109.com (ppp002-tmrv.injersey.com [206.139.59.2]) by hiway1.exit109.com (8.7.6/8.6.9) with SMTP id RAA22609 for ; Sat, 30 Nov 1996 17:45:24 -0500 (EST) X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <1.5.4.32.19961130224404.006cb5ec@hiway1.exit109.com> X-Sender: pbakelaar@hiway1.exit109.com X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Phil Bakelaar Content-Type: text/plain; charset="us-ascii" Content-Length: 122 From: Phil Bakelaar Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: changing email... Date: Sat, 30 Nov 1996 17:44:04 -0500 i want to cancel this email address and start recieving it on AOL. what are the email addresses for doing this? thx ben From owner-starship-design Sat Nov 30 18:56 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["457" "Sat" "30" "November" "1996" "19:00:27" "-0800" "Steve VanDevender" "stevev@efn.org" nil "13" "starship-design: changing email..." "^From:" nil nil "11" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id SAA16537 for starship-design-outgoing; Sat, 30 Nov 1996 18:56:07 -0800 (PST) Received: from haus.efn.org (haus.efn.org [198.68.17.3]) by darkwing.uoregon.edu (8.8.3/8.8.3) with ESMTP id SAA16487 for ; Sat, 30 Nov 1996 18:56:05 -0800 (PST) Received: from tzadkiel.efn.org (stevev@cisco-ts17-line13.uoregon.edu [128.223.150.230]) by haus.efn.org (8.8.3/8.7.3) with ESMTP id TAA16133; Sat, 30 Nov 1996 19:03:50 -0800 (PST) Received: (from stevev@localhost) by tzadkiel.efn.org (8.8.3/8.8.3) id TAA24626; Sat, 30 Nov 1996 19:00:27 -0800 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199612010300.TAA24626@tzadkiel.efn.org> In-Reply-To: <1.5.4.32.19961130224404.006cb5ec@hiway1.exit109.com> References: <1.5.4.32.19961130224404.006cb5ec@hiway1.exit109.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Steve VanDevender Content-Type: text Content-Length: 456 From: Steve VanDevender Sender: owner-starship-design To: Phil Bakelaar Cc: starship-design@lists.uoregon.edu Subject: starship-design: changing email... Date: Sat, 30 Nov 1996 19:00:27 -0800 Phil Bakelaar writes: > i want to cancel this email address and start recieving > it on AOL. what are the email addresses for doing this? > > thx > ben Mail to majordomo@lists.uoregon.edu and put only the words "info starship-design" into the body of the message for information on how to unsubscribe and resubscribe. All you should need to do is unsubscribe by sending the request from your current address and resubscribe using your AOL account. From owner-starship-design Sun Dec 1 13:04 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7596" "Sun" "1" "December" "1996" "16:07:42" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "145" "Re: starship-design: Mission Structure" "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id NAA06858 for starship-design-outgoing; Sun, 1 Dec 1996 13:04:50 -0800 (PST) Received: from emout07.mail.aol.com (emout07.mx.aol.com [198.81.11.22]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id NAA06831 for ; Sun, 1 Dec 1996 13:04:46 -0800 (PST) Received: by emout07.mail.aol.com (8.6.12/8.6.12) id QAA27158 for starship-design@lists.uoregon.edu; Sun, 1 Dec 1996 16:07:42 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961201160740_806732908@emout07.mail.aol.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: KellySt@aol.com Content-Type: text Content-Length: 7595 From: KellySt@aol.com Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: Re: starship-design: Mission Structure Date: Sun, 1 Dec 1996 16:07:42 -0500 Hi Nick, welcom back online! > Hi everyone. >Kelly wrote: >>This presuposes you want and can afford a colony there. Given one would be >>very expensive to maintain (all those long supply flights), its unlikely to >>be maintained. Be self sufficent would require a huge population and >>investment in equipment. Which seems unwarrented. We also haven't >>identified a reason to colonize there. >>If you did want to colonize their you wouldn't want to go to the planets. >>Its harder to find and process raw materials their, and since you can't use >>the biosphere anyway, build a space colony. >What's the point of a hugely expensive manned trip there and back? With > advances in computer and robot technology, probes could surely perform this > task at much reduced cost, and with a powerful communication laser / maser, >wouldn't even need to make the return journey. The only motive for a manned > flight would be an extended stay and a very thorough on-site inspection of >the planets / stellar system. If this is to be done, I don't see that a > permanent presence would be so much more difficult or expensive. Compared > to the cost of shifting many millions of tons from Earth to TC within a few > years, the cost of maintaining a presence in-system can't be all that > astronomical. You wouldn't need a continuous flow if supply flights. Food > and supplies would be taken on the initial flight, and a major component of > the mission would be to set up a self sustaining biosystem, either on a > planet or in space (I feel that a planet, despite the disadvantages of the > gravity well, would have such psychological advantages that it should not > be dismissed lightly). Biotechnology is one of the most rapidly advancing > areas of knowledge right now. I think we can be fairly confident that > within a hundred years or so 'designer' organisms could be created > specifically for colinization purposed. A pathfinder probe sent before the > main mission to gather data on the planet(s) might make it possible for > plants to be engineered to survive in the 'open,' which would make > planet-bound base easier to set up - space would not have to be made within > the base for food crops (of course, plants/algae for oxygen generation > would still have to kept within the base. For maximum efficiency, I would > envisage separate, specisialist organisms designed for the two main > purposes of food and O2). Several good questions, some with no firm answers. The ship as defined would be capable of a stay of several years, which should allow fair extensive rough surveys of everything, but a much longer stay would not be possible without a much great sized flight. Say at least 10-100 times the scales we were talking about to sustain a more indefinate colony/base. Given that the origional team would be geting rather old anyway (thus risking that they and their ship couldn't make it back) you might as well just expect follow on flights every 5-10 years. I can't see how we could justify the much larger initial flight to a place we don't know of any particular reason to want to stay at. Avoiding any plantary bioshpere is important for 2 reasons. First you'ld want to study it, which teraforming it would make impossible. Secound it would be EXTREMLY dangerous to the crew. Discovering a biohazard could easily decimate the crew before they could deal with it, and make earth unwilling to allow them to return, or other personel/supplies to be launched to them. In general scaling up from an expidition that could hang around for a few years, to one that could hange around for decades would increase the scale and cost by orders of magnitude. Given its hard to imagine people funding the smaller flight, the larger seems impossible to justify. Certainly science has never been a reason to fund projects of this scale, and the novelty of seting up a non selfsustaining colony doesn't seem practical (and also never worked in the past). As an example consider how this would play if we were discusing seting up a colony in Antarctica. Certainly the south polar reagions of this planet are far more habitable then any other planet were likly to find. Seting up the colony would be rediculasly cheap in comparison. But why would we set up a city of hudreds of thosands of people (probably the smallest scale capable of being self sustaining) in antarctica, or the deep oceans, or isolated deep deserts, etc? It could be technically chalenging, could be a base for scientific investigation, be an area where a new culture could develop, make it harder for humans to be whiped out in case of a global catastrophy, etc... But would any of those justify the huge initial expence to the public? > The other relevant technology, also undergoing rapid advancement at > present, is virtual reality. The psychological impact of spending long > periods of time - perhaps an entire lifetime - away from Earth would be > diminished, perhaps eliminated, by the availability of highly realistic VR > systems, possibly indistinguishable from reality. Updates could be sent > regularly from Earth to keep the simulations up-to date. TC could be kept > no more than 10 years (or whatever the Earth-TC light distance is) behind > Earth in this way. The idea of replacing reality with simulations might >seem a horifc idea to us, but we must bear in mind the social and >collective psychological changes that may well occur in our culture as VR >is developed. I can imagine the distinction between reality and simulation >that seems so important to us being much less of an issue in a generation >or two (of course, colonists would still spend most of their time in the >'real' world doing scientific research and construction work.) We must >therefore consider the possibility that getting home might not be a major >issue for the colonists - or at least that people for whom this would be >true could be chosen for the mission. I think you overestimating the importance of VR. Yes the could watch old VR TV from earth, and image pictures from the teatons would be nice, but also keep being a disturbing contrast from your situation. I.E. things are happening in the huge rapidly changing culture technology back on Earth and in the solar system. But you are stuck in a small ship/base, with a few people, knowing your more and more professionally dated. In fact you might correctly suspect that back home people are building large careers out of analizing your data. While you are to busy to do more then collect and forward it. > A large enough gene pool for a > self-sustaining colony could perhaps be squeezed into the Asimov (are we >still calling it this?), I never called it that. ;) < snip genetic concerns> > I really believe that some kind of colonisation is required to justify a >manned mission of the scale we have been considering. The only benefit >that, in my opinion, could possibly outweight the almost globally crippling >cost of the program would be a major social advancement of humanity (a two >starsystem culture - I have thought of many advantages of such a culture >which I won't go into here). A colonization mission would add so much to >the return from the massive investment, for a proportional increase in cost >which, for a culture presumably with colonization experience within the >solar system, would not be excessive. >Nick Tosh The question is how even to justify a colony, much less how to use a colony to justify the mission. Siccessfully colonies are not build for the sake of building colonies. Kelly From owner-starship-design Sun Dec 1 15:01 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1119" "Sun" "1" "December" "1996" "18:04:38" "-0500" "Breedztar@aol.com" "Breedztar@aol.com" nil "23" "starship-design: new email..." "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id PAA14236 for starship-design-outgoing; Sun, 1 Dec 1996 15:01:44 -0800 (PST) Received: from emout17.mail.aol.com (emout17.mx.aol.com [198.81.11.43]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id PAA14222 for ; Sun, 1 Dec 1996 15:01:40 -0800 (PST) Received: by emout17.mail.aol.com (8.6.12/8.6.12) id SAA22297 for starship-design@lists.uoregon.edu; Sun, 1 Dec 1996 18:04:38 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961201180438_1553939709@emout17.mail.aol.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Breedztar@aol.com Content-Type: text Content-Length: 1118 From: Breedztar@aol.com Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: new email... Date: Sun, 1 Dec 1996 18:04:38 -0500 hi everybody this is ben i participated alot in the summer incase you don't remember me. anyway i have two things to say. #1 please check out my starship-design homepage and tell me what you think. mostly its just put together from some web pages of some members. of course, i plan on adding more as time goes on. also, tell me if there are other starship-design pages out there. also, david or steve v., i dont know who it is i should ask, but do you mind? does anyone else mind? #2 i want to start a #starship-design channel on the undernet (internet relay chat) and i need 10 email addresses. of course i could get them from when we used to have the CC list, the reason i am asking is out of courtesy. all you do is tell me i can use your email address and when i have 10 i submit a petition to undernet for the creation of a #starship-design channel.. i don't know how popular this would be, but hey, any new medium is good. if anyone has questions about irc, just email them to me directly, not over the starship-design list. also, i lost track of the new LIT site address. can someone email me it? adios ben From owner-starship-design Mon Dec 2 12:45 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1320" "Mon" "2" "December" "1996" "12:45:05" "-0800" "Steve VanDevender" "stevev@darkwing.uoregon.edu" nil "30" "starship-design: testers wanted" "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id MAA12378 for starship-design-outgoing; Mon, 2 Dec 1996 12:45:07 -0800 (PST) Received: (from stevev@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id MAA12353; Mon, 2 Dec 1996 12:45:05 -0800 (PST) X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199612022045.MAA12353@darkwing.uoregon.edu> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Steve VanDevender Content-Type: text Content-Length: 1319 From: Steve VanDevender Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: testers wanted Date: Mon, 2 Dec 1996 12:45:05 -0800 (PST) I've been working on a small project to test some of the ideas I want to use in a more elaborate relativistic simulator. The result is a program that graphically displays the effects of relativistic motion at constant velocity or with constant acceleration, including color effects of doppler-shifting on a color display (it should work with 8-bit colormapped displays or 15-, 16-, and 24-bit true color displays). It displays either a randomly-generated star field or a cubic lattice of stars, and you can specify many parameters like velocity, acceleration, time scale, and number of stars to display using command-line arguments. To run this program, you need: A version of UNIX with the gettimeofday() system call (known to work in Linux, Digital UNIX, and Solaris; probably most other modern UNIXen will work) X11R5 or later (only the Xt and X11 libraries are used) An ANSI C compiler (tested with gcc and Digital UNIX cc) Probably some amount of programming knowledge about C, UNIX, and X I haven't worked up elaborate documentation about the program, so you may need to be willing to read the source code to figure out how it works. If you're interested in looking at it send me mail privately and I'll mail you the source. I'll also try to get some preliminary documentation done for ease of testing. From owner-starship-design Tue Dec 3 18:03 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["328" "Tue" "3" "December" "1996" "21:06:09" "-0500" "Breedztar@aol.com" "Breedztar@aol.com" nil "9" "starship-design: Stellar Engine Page..." "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id SAA04600 for starship-design-outgoing; Tue, 3 Dec 1996 18:02:51 -0800 (PST) Received: from emout07.mail.aol.com (emout07.mx.aol.com [198.81.11.22]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id SAA04581 for ; Tue, 3 Dec 1996 18:02:47 -0800 (PST) Received: by emout07.mail.aol.com (8.6.12/8.6.12) id VAA04328 for starship-design@lists.uoregon.edu; Tue, 3 Dec 1996 21:06:09 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961203210608_707136059@emout07.mail.aol.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Breedztar@aol.com Content-Type: text Content-Length: 327 From: Breedztar@aol.com Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Stellar Engine Page... Date: Tue, 3 Dec 1996 21:06:09 -0500 Thought some of you might be interested.... Some of you might've already found it, but it can't hurt to say once more. This is a page about a Stellar Engine theory using fractal shape changing robots.. Take off the stellar.htm to get to the fractal shape changing robots page. http://www.stellar.demon.co.uk/stellar.htm Ben From owner-starship-design Wed Dec 4 01:55 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["910" "Wed" "4" "December" "1996" "10:59:56" "+0100" "Timothy van der Linden" "TLG.van.der.Linden@tip.nl" nil "34" "starship-design: Re: Stellar Engine Page..." "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id BAA27866 for starship-design-outgoing; Wed, 4 Dec 1996 01:55:45 -0800 (PST) Received: from parijs.tip.nl (parijs.tip.nl [143.177.1.10]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id BAA27856 for ; Wed, 4 Dec 1996 01:55:42 -0800 (PST) Received: from hengelo21.pop.tip.nl by parijs.tip.nl with smtp (Smail3.1.29.1 #16) id m0vVEDD-000Dm6C; Wed, 4 Dec 96 11:05 MET X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: X-Sender: t596675@pop1.tip.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 909 From: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Stellar Engine Page... Date: Wed, 04 Dec 1996 10:59:56 +0100 What a coincidence :( >Date: Wed, 16 Oct 1996 08:35:55 -0500 >To: starship-design@lists.uoregon.edu >From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) >Subject: starship-design: Stellar drive? > >Stumbled across a web site in Britian describing an idea for a web site >using asymetric micrpulses of magnatism. Its eiather very clever, or >stuipid; and I'm to tired to figure out which. URL and cliping from intro >follows. > >Kelly > >----------------------------------------------------------------- > >http://www.stellar.demon.co.uk/stellar.htm Timothy >Thought some of you might be interested.... Some of you might've already >found it, but it can't hurt to say once more. This is a page about a Stellar >Engine theory using fractal shape changing robots.. Take off the stellar.htm >to get to the fractal shape changing robots page. > >http://www.stellar.demon.co.uk/stellar.htm > >Ben From owner-starship-design Wed Dec 4 03:52 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["190" "Wed" "4" "December" "1996" "06:55:32" "-0500" "Breedztar@aol.com" "Breedztar@aol.com" nil "6" "starship-design: Re: Stellar Engine Page..." "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id DAA05555 for starship-design-outgoing; Wed, 4 Dec 1996 03:52:01 -0800 (PST) Received: from emout10.mail.aol.com (emout10.mx.aol.com [198.81.11.25]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id DAA05544 for ; Wed, 4 Dec 1996 03:51:59 -0800 (PST) Received: by emout10.mail.aol.com (8.6.12/8.6.12) id GAA27660 for starship-design@lists.uoregon.edu; Wed, 4 Dec 1996 06:55:32 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961204065531_1253128804@emout10.mail.aol.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Breedztar@aol.com Content-Type: text Content-Length: 189 From: Breedztar@aol.com Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Stellar Engine Page... Date: Wed, 4 Dec 1996 06:55:32 -0500 That's funny! I didn't know Kelly had already told us about it. I never saw it... but anyway, for anyone who went there, what did you think of its validity and scientific correctness? Ben From owner-starship-design Wed Dec 4 07:32 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["407" "Wed" "4" "December" "1996" "16:35:58" "+0100" "Timothy van der Linden" "TLG.van.der.Linden@tip.nl" nil "15" "starship-design: Re: Stellar Engine Page..." "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id HAA29560 for starship-design-outgoing; Wed, 4 Dec 1996 07:32:41 -0800 (PST) Received: from parijs.tip.nl (parijs.tip.nl [143.177.1.10]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id HAA29527 for ; Wed, 4 Dec 1996 07:32:33 -0800 (PST) Received: from hengelo15.pop.tip.nl by parijs.tip.nl with smtp (Smail3.1.29.1 #16) id m0vVJSO-000DlSC; Wed, 4 Dec 96 16:41 MET X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: X-Sender: t596675@pop1.tip.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Content-Type: text/plain; charset="us-ascii" Content-Length: 406 From: TLG.van.der.Linden@tip.nl (Timothy van der Linden) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: Re: Stellar Engine Page... Date: Wed, 04 Dec 1996 16:35:58 +0100 Ben wrote: >That's funny! I didn't know Kelly had already told us about it. I never saw >it... but anyway, for anyone who went there, what did you think of its >validity and scientific correctness? Hmm, you must really have been off line for a while, several replies had been sent to SD in that time. I'll sent them to you once more. [Boy, are you sorry you asked, there are over 20 messages] Timothy From owner-starship-design Wed Dec 4 08:54 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["763" "Wed" "4" "December" "1996" "17:56:00" "+0100" "Zenon Kulpa" "zkulpa@zmit1.ippt.gov.pl" nil "21" "Re: starship-design: Stellar Engine Page..." "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id IAA28787 for starship-design-outgoing; Wed, 4 Dec 1996 08:54:04 -0800 (PST) Received: from zmit1.ippt.gov.pl (zmit1.ippt.gov.pl [148.81.53.40]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id IAA28753 for ; Wed, 4 Dec 1996 08:53:57 -0800 (PST) Received: by zmit1.ippt.gov.pl (4.1/SMI-4.1) id AA16453; Wed, 4 Dec 96 17:56:00 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <9612041656.AA16453@zmit1.ippt.gov.pl> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: zkulpa@zmit1.ippt.gov.pl (Zenon Kulpa) Content-Type: text Content-Length: 762 From: zkulpa@zmit1.ippt.gov.pl (Zenon Kulpa) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Cc: zkulpa@ippt Subject: Re: starship-design: Stellar Engine Page... Date: Wed, 4 Dec 96 17:56:00 +0100 > From: Breedztar@aol.com > > Thought some of you might be interested.... Some of you might've already > found it, but it can't hurt to say once more. This is a page about a Stellar > Engine theory using fractal shape changing robots.. > Not exactly. The stellar engine concept (discussed previously on this list) is quite separate from the fractal robots concept. > Take off the stellar.htm > to get to the fractal shape changing robots page. > Another interesting fractal robot concept was elaborated in R. Forward's book Rocheworld, under the name "Christmas Bush". The book is interesting also because it pictures a one-way, laser-beam/sail powered mission (to Barnard's star, ~6 ly away), and discusses rationale for such a type of mission. -- Zenon From owner-starship-design Wed Dec 4 09:18 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["444" "Wed" "4" "December" "1996" "11:21:00" "-0600" "Lora Flinn" "lflinn@ja2.jsc.nasa.gov" nil "13" "starship-design: New to List" "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id JAA15076 for starship-design-outgoing; Wed, 4 Dec 1996 09:18:05 -0800 (PST) Received: from jsc-ems-gws06.jsc.nasa.gov (jsc-ems-gws06.jsc.nasa.gov [139.169.22.17]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id JAA15052 for ; Wed, 4 Dec 1996 09:18:02 -0800 (PST) Received: by jsc-ems-gws06.jsc.nasa.gov with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.994.57) id <01BBE1D5.AF7F4DA0@jsc-ems-gws06.jsc.nasa.gov>; Wed, 4 Dec 1996 11:24:17 -0600 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.994.57 Encoding: 12 TEXT Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: "Flinn, Lora" Content-Type: text Content-Length: 443 From: "Flinn, Lora" Sender: owner-starship-design To: Star Design Subject: starship-design: New to List Date: Wed, 4 Dec 1996 11:21:00 -0600 Hello, My name is Lora and I am new to the list. I work at NASA in Houston as an audio engineer and sound designer for JSC's television contractor. I have been enjoying the list for about a week now. I have noted the discussion is focusing on Stellar drive. Has the Plasma Engine, being developed By Dr Franklin Chang Diaz been discussed? If not I can gather some data and submit to the list. It uses plasma contained by magnets. Cheers From owner-starship-design Wed Dec 4 09:23 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["916" "Wed" "4" "December" "1996" "12:27:56" "-0500" "David Levine" "David@interworld.com" nil "31" "RE: starship-design: New to List" "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id JAA16935 for starship-design-outgoing; Wed, 4 Dec 1996 09:23:52 -0800 (PST) Received: from www1.interworld.com (www.InterWorld.Com [165.254.130.4]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id JAA16896 for ; Wed, 4 Dec 1996 09:23:49 -0800 (PST) Received: by www1.interworld.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.993.5) id <01BBE1DE.955007E0@www1.interworld.com>; Wed, 4 Dec 1996 12:27:58 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.993.5 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: David Levine Content-Type: text/plain; charset="us-ascii" Content-Length: 915 From: David Levine Sender: owner-starship-design To: "'starship-design@lists.uoregon.edu'" Subject: RE: starship-design: New to List Date: Wed, 4 Dec 1996 12:27:56 -0500 Welcome to the list. Both Kelly and I used to work at JSC - what building are you in? And certainly, any data you wish to submit is more than welcome. ------------------ David Levine InterWorld Technology Ventures, Inc. "A stroke of the brush does not guarantee art from the bristles." >---------- >From: Flinn, Lora[SMTP:lflinn@ja2.jsc.nasa.gov] >Sent: Wednesday, December 04, 1996 12:21 PM >To: Star Design >Subject: starship-design: New to List > >Hello, >My name is Lora and I am new to the list. I work at NASA in Houston as >an >audio engineer and sound designer for JSC's television contractor. I >have >been enjoying the list for >about a week now. I have noted the discussion is focusing on Stellar >drive. >Has the Plasma Engine, being developed By Dr Franklin Chang Diaz been >discussed? If not I can gather some data and submit to the list. It uses >plasma contained by magnets. >Cheers > From owner-starship-design Wed Dec 4 12:00 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1685" "Wed" "4" "December" "1996" "15:03:23" "-0500" "Nick Tosh" "101765.2200@compuserve.com" nil "29" "starship-design: Mission structure" "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.3/8.8.3) id MAA09334 for starship-design-outgoing; Wed, 4 Dec 1996 12:00:22 -0800 (PST) Received: from arl-img-7.compuserve.com (arl-img-7.compuserve.com [149.174.217.137]) by darkwing.uoregon.edu (8.8.3/8.8.3) with SMTP id MAA09306 for ; Wed, 4 Dec 1996 12:00:17 -0800 (PST) Received: by arl-img-7.compuserve.com (8.6.10/5.950515) id PAA14860; Wed, 4 Dec 1996 15:03:48 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <199612041503_MC1-CA4-36FA@compuserve.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Nick Tosh <101765.2200@compuserve.com> Content-Type: text Content-Length: 1684 From: Nick Tosh <101765.2200@compuserve.com> Sender: owner-starship-design To: SD Subject: starship-design: Mission structure Date: Wed, 4 Dec 1996 15:03:23 -0500 Kelly, I just don't agree with you. I think that setting up a permanent colony would be a small matter in comparison to getting a massive exploration vessel to a nearby star system. The construction, biotechnology and genetic engineering (not to mention entertainment and psychological health) technologies are likely to advance much more rapidly in the future than relativistic speed propulsion technologies, which can surely have no application apart from the one we intend. We have been focussing on how the nearly impossible task of interstellar propulsion can be accomplished, but perhaps we've given insufficient consideration to the technologies which will continually advance due to a host of other applications. We should be thinking about how these can be used to our advantage. It is essential to consider the nature of technological advance when 'planning' future projects. What will have to be developed specially (expensive), and what will be available in any case (good value)? This is, of course, a matter of opinion, as neither of us knows for certain what areas of technology will be most developed in the coming decades. Speaking for myself, when I consider the technology required for setting up a completely self sustaining colony independent from Earth, I feel far more optimistic about the feasability of the concept than I do when I read about maser powered ion engines and the like (fascinating though such ideas are). This is a subject which has to be thought out in much more depth (as does the question of whether a colony is desirable, which, being a much more subjective issue, I feel we can leave until we have decided whether it is possible!). Nick From owner-starship-design Wed Dec 4 13:01 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5212" "Wed" "4" "December" "1996" "22:03:28" "+0100" "Zenon Kulpa" "zkulpa@zmit1.ippt.gov.pl" nil "96" "Re: starship-design: Mission structure" "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.4/8.8.4) id NAA10919 for starship-design-outgoing; Wed, 4 Dec 1996 13:01:46 -0800 (PST) Received: from zmit1.ippt.gov.pl (zmit1.ippt.gov.pl [148.81.53.40]) by darkwing.uoregon.edu (8.8.4/8.8.4) with SMTP id NAA10893 for ; Wed, 4 Dec 1996 13:01:38 -0800 (PST) Received: by zmit1.ippt.gov.pl (4.1/SMI-4.1) id AA16650; Wed, 4 Dec 96 22:03:28 +0100 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <9612042103.AA16650@zmit1.ippt.gov.pl> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: zkulpa@zmit1.ippt.gov.pl (Zenon Kulpa) Content-Type: text Content-Length: 5211 From: zkulpa@zmit1.ippt.gov.pl (Zenon Kulpa) Sender: owner-starship-design To: starship-design@lists.uoregon.edu Cc: zkulpa@ippt Subject: Re: starship-design: Mission structure Date: Wed, 4 Dec 96 22:03:28 +0100 > From: Nick Tosh <101765.2200@compuserve.com> > > Kelly, I just don't agree with you. I think that setting up a permanent > colony would be a small matter in comparison to getting a massive > exploration vessel to a nearby star system. The construction, biotechnology > and genetic engineering (not to mention entertainment and psychological > health) technologies are likely to advance much more rapidly in the future > than relativistic speed propulsion technologies, which can surely have no > application apart from the one we intend. We have been focussing on how the > nearly impossible task of interstellar propulsion can be accomplished, but > perhaps we've given insufficient consideration to the technologies which > will continually advance due to a host of other applications. We should be > thinking about how these can be used to our advantage. It is essential to > consider the nature of technological advance when 'planning' future > projects. What will have to be developed specially (expensive), and what > will be available in any case (good value)? > > This is, of course, a matter of opinion, as neither of us knows for certain > what areas of technology will be most developed in the coming decades. > Speaking for myself, when I consider the technology required for setting up > a completely self sustaining colony independent from Earth, I feel far more > optimistic about the feasability of the concept than I do when I read about > maser powered ion engines and the like (fascinating though such ideas are). > > This is a subject which has to be thought out in much more depth (as does > the question of whether a colony is desirable, which, being a much more > subjective issue, I feel we can leave until we have decided whether it is > possible!). > There was some discussion on the mission types rather long ago (mostly, my quarrel with Kelly on one-way missions :-). I want to sum up briefly my opinion on this matter: - Note that the prerequsite for starting the interstellar mission is prior start of the COLONIZATION OF THE SOLAR SYSTEM - i.e., at least establishment of permanent, ALMOST self-sustaining bases on the Moon and Mars, possibly some small space bases/colonies, routine interplanetary manned trips, at least, say, within the orbit of Jupiter, asteroid mining facilities and factories. Without this, construction in space of the huge starship, capable of sustaining significant crew without constant resupply for tens of years, as well as the solar-system-wide supporting propulsion system (huge orbiting masers/lasers, etc.) is simply not possible. Hence, the technology for building significantly large self-sustaining manned bases in space will be available at the time, that is, building of the space colony or long-duration self-sustaining base in another star system will be quite feasible and much easier than we may think today. - However, building somewhere. light-years away, a really independent colony starting new permanent human habitat there seems still a huge undertaking for me. I think, to establish something of the sort will require a whole flotilla of starships and tens of years of construction of all necessary infrastructure, possibly including terraforming of some planet. - Therefore, a much more realistic solution for me is establishing a LONG-DURATION OUTPOST BASE. That is, it calls for a so-called ONE-WAY mission. What is a difference, from the point of view of the crew, between the one-way mission and the colonization mission? There is a SINGLE difference: there is NO PROCRERATION on the one-way mission. Only this, nothing more! Hence, from technical point of view, the one-way mission is simpler and requires much smaller resources, becoming feasible in the "early colonization of the solar system" conditions outlined above. Technically, the one-way mission: -- can have much smaller crew (as the questions of genetic diversity and all sociotechnical specialization variety are absent); -- requires no provisions for rearing and educating children, which include additional crew, much more elaborate environmental control, education facilities, much more storage (or on-board industry) for all things for children and young; -- the outpost does not have to be indefinitely sustainable - it would suffice to stay operational till the longest possible natural life of the crew, which means some 50+ years only, certainly less than 100. - The outpost may be later transformed into a permanent colony, if the conditions in the target system show to be good enough and the technological advances within the solar system during the time of the trip and initial exploration phase (this means some 20 years of Earth time...) will allow for sending follow-up starships with enough resources to establish a colony. So, I thing that the course of events will be like this: - robotic "pathfinder" probe (testing the starship technology and preliminary assessing of the conditions for subsequent stages); - one-way outpost construction mission; - possible follow-up colonization expeditions. -- Zenon From owner-starship-design Thu Dec 5 20:28 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2821" "Thu" "5" "December" "1996" "23:32:23" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "50" "Re: starship-design: Mission structure" "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.4/8.8.4) id UAA21740 for starship-design-outgoing; Thu, 5 Dec 1996 20:28:48 -0800 (PST) Received: from emout13.mail.aol.com (emout13.mx.aol.com [198.81.11.39]) by darkwing.uoregon.edu (8.8.4/8.8.4) with SMTP id UAA21729 for ; Thu, 5 Dec 1996 20:28:45 -0800 (PST) Received: by emout13.mail.aol.com (8.6.12/8.6.12) id XAA27222 for starship-design@lists.uoregon.edu; Thu, 5 Dec 1996 23:32:23 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961205233212_906581277@emout13.mail.aol.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: KellySt@aol.com Content-Type: text Content-Length: 2820 From: KellySt@aol.com Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: Re: starship-design: Mission structure Date: Thu, 5 Dec 1996 23:32:23 -0500 > From: Nick Tosh <101765.2200@compuserve.com> > > Kelly, I just don't agree with you. I think that setting up a permanent > colony would be a small matter in comparison to getting a massive > exploration vessel to a nearby star system. The construction, biotechnology > and genetic engineering (not to mention entertainment and psychological > health) technologies are likely to advance much more rapidly in the future > than relativistic speed propulsion technologies, which can surely have no > application apart from the one we intend. We have been focussing on how the > nearly impossible task of interstellar propulsion can be accomplished, but > perhaps we've given insufficient consideration to the technologies which > will continually advance due to a host of other applications. We should be > thinking about how these can be used to our advantage. It is essential to > consider the nature of technological advance when 'planning' future > projects. What will have to be developed specially (expensive), and what > will be available in any case (good value)? > > This is, of course, a matter of opinion, as neither of us knows for certain > what areas of technology will be most developed in the coming decades. > Speaking for myself, when I consider the technology required for setting up > a completely self sustaining colony independent from Earth, I feel far more > optimistic about the feasability of the concept than I do when I read about > maser powered ion engines and the like (fascinating though such ideas are). > > This is a subject which has to be thought out in much more depth (as does > the question of whether a colony is desirable, which, being a much more > subjective issue, I feel we can leave until we have decided whether it is > possible!). > I agree, but in one sence the two techs are locked together. current estimates are that it requres (with current tech) a population of several million people to maintain an independant, selfsustaining, industrial society. (Obviousl a pre industrial society take far fewer, but couldn't survive as a space colony.) I'm willing to assume for discusion, that high tech in the mid 21st century could lower that to 100,000. But given that our current ship designs can carry less than a thousand people at hellish cost. This two order of magnitude passenger/cost jump would be EXTREAMLY hard to justify. If you assume the tech is much higher than that (i.e. lowering the number of people need to sustain the society), you have to assume it invalidates a lot of the assumptions of our basic designs and mission concepts. So, a colony stays outside the bounds of the possible. Beyond that we'ld have to argue about why they'ld want to set up a colony in a place they know nothing about (except its hard to get to and support)? Kelly From owner-starship-design Thu Dec 5 20:38 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1459" "Thu" "5" "December" "1996" "23:42:06" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "45" "Re: RE: starship-design: New to List" "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.4/8.8.4) id UAA23758 for starship-design-outgoing; Thu, 5 Dec 1996 20:38:22 -0800 (PST) Received: from emout19.mail.aol.com (emout19.mx.aol.com [198.81.11.45]) by darkwing.uoregon.edu (8.8.4/8.8.4) with SMTP id UAA23678 for ; Thu, 5 Dec 1996 20:38:18 -0800 (PST) Received: by emout19.mail.aol.com (8.6.12/8.6.12) id XAA19042 for starship-design@lists.uoregon.edu; Thu, 5 Dec 1996 23:42:06 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961205234204_1986205374@emout19.mail.aol.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: KellySt@aol.com Content-Type: text Content-Length: 1458 From: KellySt@aol.com Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: Re: RE: starship-design: New to List Date: Thu, 5 Dec 1996 23:42:06 -0500 >From: Flinn, Lora[SMTP:lflinn@ja2.jsc.nasa.gov] >Sent: Wednesday, December 04, 1996 12:21 PM >To: Star Design >Subject: starship-design: New to List > >Hello, >My name is Lora and I am new to the list. I work at > NASA in Houston as an audio engineer and sound designer > for JSC's television contractor. I have been enjoying the > list for about a week now. I have noted the discussion > is focusing on Stellar drive. >Has the Plasma Engine, being developed By Dr Franklin > Chang Diaz been discussed? If not I can gather some data > and submit to the list. It uses plasma contained by magnets. >Cheers > Welcome to the discusion Lora! Hope you enjoy it here. You might want to check out the website we have which have old discusions and articals written up on topics. A new one in work The new site we're using for the new draft documents are at: http://165.254.130.90/LIT/InterStellar/ http://urly-bird/LIT/InterStellar/ Our old web site (with back newsletters) and other material is at: http://sunsite.unc.edu/lunar/ The school of starship design is the part you'ld be most interested in. Not sure what you mean about the plasma drive. Couldn't hurt to upload some data. It sounds like a small low power thruster idea I heard about for satelight station keeping. We have tossed around lots of drive ideas, some using plasmas. Basically we need a HUGE amount of power for thrust. Anyway, welcome to the group. Kelly Starks From owner-starship-design Sat Dec 7 07:35 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["530" "Sat" "7" "December" "1996" "10:39:19" "-0500" "Breedztar@aol.com" "Breedztar@aol.com" nil "14" "starship-design: members pages..." "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.4/8.8.4) id HAA23093 for starship-design-outgoing; Sat, 7 Dec 1996 07:35:16 -0800 (PST) Received: from emout01.mail.aol.com (emout01.mx.aol.com [198.81.11.92]) by darkwing.uoregon.edu (8.8.4/8.8.4) with SMTP id HAA23072 for ; Sat, 7 Dec 1996 07:35:07 -0800 (PST) Received: by emout01.mail.aol.com (8.6.12/8.6.12) id KAA06533 for starship-design@lists.uoregon.edu; Sat, 7 Dec 1996 10:39:19 -0500 X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-ID: <961207090128_1186639522@emout01.mail.aol.com> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Breedztar@aol.com Content-Type: text Content-Length: 529 From: Breedztar@aol.com Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: members pages... Date: Sat, 7 Dec 1996 10:39:19 -0500 hey, everyone, i figgered id try once again to collect member info and stuff... my starship-design homepage is http://nj5.injersey.com/~bakelaar/abraxas/starship-design and if you wanna check it out, thats ok, but all i really want is information: if you have your own homepage, please email me the url, otherwise if you want a quickie info page on yourself, email me the info, ill put it up there. thanx also, stuff like job occupation and stuff for each member might be cool to put up. whatever you wanna give me. adios ben From owner-starship-design Tue Dec 17 14:04 PST 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["490" "Tue" "17" "December" "1996" "14:04:04" "-0800" "Steve VanDevender" "stevev@darkwing.uoregon.edu" nil "14" "starship-design: relativity simulator web pages" "^From:" nil nil "12" nil nil nil nil] nil) Received: (from majordom@localhost) by darkwing.uoregon.edu (8.8.4/8.8.4) id OAA27124 for starship-design-outgoing; Tue, 17 Dec 1996 14:04:06 -0800 (PST) Received: (from stevev@localhost) by darkwing.uoregon.edu (8.8.4/8.8.4) id OAA27087; Tue, 17 Dec 1996 14:04:04 -0800 (PST) X-Authentication-Warning: darkwing.uoregon.edu: majordom set sender to owner-starship-design using -f Message-Id: <199612172204.OAA27087@darkwing.uoregon.edu> Errors-To: owner-starship-design@lists.uoregon.edu Precedence: bulk Reply-To: Steve VanDevender Content-Type: text Content-Length: 489 From: Steve VanDevender Sender: owner-starship-design To: starship-design@lists.uoregon.edu Subject: starship-design: relativity simulator web pages Date: Tue, 17 Dec 1996 14:04:04 -0800 (PST) I've created some web pages for the simple relativistic motion simulator I mentioned a few weeks ago, with sample images and source code available. The URL is: http://hexadecimal.uoregon.edu/relativity At least those of you who aren't able to run the simulator can see sort of what it looks like. I've spent enough time on it today, but I still need to get to the task of explaining the physics and astrophysics behind how it all works and why things look so weird at high velocities.