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Re: RE: starship-design: Timothy's beamed power paper

In a message dated 7/27/97 8:50:36 AM, zkulpa@zmit1.ippt.gov.pl (Zenon Kulpa)

>> From: KellySt@aol.com
>> In a message dated 7/25/97 12:54:35 PM, (Zenon Kulpa) wrote:
>> >> From: KellySt@aol.com
>> >>
>> >> [...]
>> >> Note this assumes you can economically replace the plasma mirror mass.
>> >> If you lose to much mass, you wouldn't be able to carry enough  
>> >> to sustain the mirror durring the deceleration phase.
>> >> 
>> >> Oh, note that the mirror plasma will get hot! Probably enough 
>> >> to explode outward in all directions. This blast presure might 
>> >> be tapable to provide a bit of rocket thrust. 
>> >> My gut feel is that woldn't work thou.
>> >
>> >Of course you can use such heated plasma as a rocked exhaust,
>> >why not?
>> It being blasted straight forward by the beam.  I'm not sure how the ship
>> could tap its reaction for thrust.
>Make the arrangement as follows:
>Warning: ASCII art follows (use a fixed font to view)
>      __________
>     |          |
>     \__        | <-the ring-shaped ship (cross-section)
>        \__     |
>  <===     \____|
>        *        <-----
>      * * *   <--------  plasma-producing beam
>        *   ____ <-----
>  <===   __/    |
>      __/       |
>     /          |
>     |__________|          
>   **   exploding plasma
>  <==   plasma exhaust
>It will just work like a stream-jet engine.

But the kinetic energy reaction is mainly between the beam and the plasma.
 The ships out of the loop.  It would need to tap into it in some secoundary
manor.  But I do think the induced heat would cause the plasma to expand out
sideways.  So you should be able to do the rocket nozzel trick.  Assuming the
beam doesn't blast it out forward of the ship like a leaf in a fire hose.
 I.E. the expansion takes place about 100,000 miles ahead of you.  <Well at
least that should take care of clearing a path ahead of the ship.>  ;)

>> >>[...]
>> >> Since the sail can be any size you want. I scaled it to about 400 times

>> >> the dry weight of the ship. That would let it decelerate from 
>> >> about 40%-43%(?) of light speed. 
>> >> Giving you a quick trip.  For the ride back you mine more lithium-6. 
>> >> Burn it all accelerating back toward Sol. They deploy a
>> >> compartivly tiny drag sail to decelerate you down into Sol  
>> >> (assuming someone  will turn on the beam again).
>> >> 
>> >And assuming you will be able to find the beam in the vastness of
>> Beam is locked in a straight line for the flight duration.  
>> If you drift off, you'll know where you left it.
>Will there be a nice striped poles along it to mark its course?
>More importantly, it will not be straight - as we have calculated 
>some time ago, it will veer to the sides by hundreds (or thousands) 
>of kilometers every time some of the transmitter maintenance crew 
>sneezes or a stray comet wanders nearby..

Well if you have a fleet of transmitter stations scattered over hundreds of
thousand, to millions of miles the crew screw-up should be handelable.  And
you only are firing the beam for a few years, so the comets can be avoided by
scheduling the flight.

As for the pole.  Make the center of the beam have a noticable carriour
signal.  Track the ship on that.

>> >-- Zenon
>> >
>> >PS. Kelly, what happened to your charming spelling?
>> >    I'm rely worrid about yor helth or somthing...  ;-))   -- Z
>> Should be worse with me typing these at night in bad light.  
>> (desk lamp burned out.)  ;)
>Oh, just this is my problem - 
>it should be (much) worse, but isn't. 
>Why? (wondered Zenon).

Dumb luck?  Perhaps I'm statistically more likely to accidentally hit the
right key, then on purpose?  ;)

>-- Zenon