Re: Fwd: LIT e-mail discussion group

[kgstar@most.magec.com (Kelly Starks x7066 MS 10-39)]

Ah, its been about a week since I sent out my draft summarry document
(attached), and (other then Daves compliment) I haven't heard any responce
to it.  No one has any complaints, things they want added, changed etc?

Kelly




At 11:29 AM 1/23/96, Kelly Starks x7066 MS 10-39 wrote:
>Ok, here my first cut of a summary of all the options we've come up with.
>(or at least all I can remember.)  I figure this is the next step up from
>Zenons proposed table of contents.  We might want to work this up to a
>summary or central reference page for the LIT server.  (More detailed
>secoundary pages could brach off it.)  I'll do more as I get some time.  (I
>working to finish the first draft of my secound novel!  So I'll be
>preoccupeid)
>
>Please review and comment.
>
>Kelly
>
>
>
>
>============================================================
> Mission flight type
>---------------------------------
>One-way
>		* Suicide (explore and die before your time when supplies end)
>		* One-way (Enough supplies are shipped to stay in target system until
>natural death)
>	
>
>(For some inexplicable reason this option has one or two strong advocates
>within L.I.T..  I want it absolutely known that I neither approve or in
>anyway support such an option.  Nor would I in any credible situation
>expect it to generate anything but revulsion among the general tax paying
>public.  Kelly Starks - The Author.)
>
>>Pros
>The ship need only be designed for a one time, one way flight.  This limits
>the technical mission risk and requires less resources.
>
>Least likelihood of back contaminating Earth.
>
>Establishes temporary outpost in starsystem.
>
>Allows investigation of the starsystem to continue until al exploration
>resources are exhausted or worn out.  Presumably for a decade or so,
>depending on the service life of the shuttles or their support facilities,
>or the service life of the remotes.
>
>>Cons
>To put it mildly the public acceptance of sending explorers out to die the
>mission and die on the frontier is low.  Risking dying maybe, but
>assigned/left to die by superiors -- no way.  Every politician within ear
>shot will run in front of the closest camera to announce that he or she
>will personally lead the witch-hunt to track down everyone connected with
>suggesting this idea.
>
>It has been suggested (adamantly) by some members of the group, that this
>might be justifiable under some situation, or that this would be acceptable
>as a colonization mission, especially if the colony could be made
>completely self sufficient from the start.  Aside from the technical
>impossibility of doing the latter.  Its unlikely in the extreme, that such
>risks would be acceptable in an initial mission.  At the very least the
>mission would have to be designed as a two way flight with the option of
>founding a colony or outpost.  Also their would be considerable debate as
>to why we would want to set up a permanent outpost in a place we don't know
>anything about, and have no idea if we'd want to stay at.  This debate
>would get louder when the continuing cost of supply flights was discussed.
>
>Other problems would be:
>
>The potential supply of skilled personnel would obviously drop, if they
>knew they were to be abandoned in the system when they finished the
>mission. Especially given that their project life expectancy (due to the
>lack of 'modern' medical facilities) would drop by a few decades, all but a
>few years of which they'd spend trapped in a traveling, or derelict ship.
>
>Lower information return to Earth due to limited baud rates of interstellar
>communication.
>
>Projected types of crew termination
>  - Voluntary suicide at end of exploration phase of mission.
>This is likely as some crewmen decide to avoid living out the rest of their
>years imprisoned in a derelict ship.
>
>  - Death due to catastrophic failure of vital ship systems as the ship
>wears out.
>Obviously the ships systems won't last forever, and can't be rebuilt or
>replaced completely.  At some point it will simply wear out and fail.  This
>could be a single failure, like a major structural breach of the habitation
>or support systems due to metal fatigue.  Or a accumulation of lesser
>failure as sub-systems begin to unravel.
>
>  - Death due to medical limitations.
>Given the limited medical facilities and personnel available on the ship.
>Crew life expectancies would be far less than those who stayed at home with
>access to modern medical care.  Given the mid 21st century high-tech
>population would conservatively have a projected life expectancy of 100-130
>years, with elongated vigorous years.  (Some estimates are far higher.)
>The crews limited medical life expectancy may still be nearly current US
>norms.
>
>  - Death due to chronic crew failure.
>At some point the crew will simply be to old to maintain and operate the
>ship, or provide their own medical care.  At this point, without a follow
>on generation to rescue or care for them, they will slowly or quickly die
>off due to a combination of the above listed causes.
>
>
>---------------------------------
>Round trip (Crew returns to Earth with ship at mission end.)
>
>>Pros
>Simplest option, and one with little likely hood of public objection.
>
>More likely to get more volunteers and better qualified volunteers for flight.
>
>This option implies that the mission is fairly short. I.E. within the
>professional life of the crew.  This would imply its short enough to return
>information in a useful amount of time.  (I.E. it would get there and back,
>before a later faster flight could do it.)
>
>It would return far more information than an interstellar communications
>link could manage.
>
>It obviously avoids the grisly public relations and crew morale problems of
>a one way mission.
>
>>cons
>Technically more challenging.  Getting a ship to the target starsystem is
>hard enough.  Getting it back would make it harder.  But this must be
>traded off against the added complexity of a ship capable of supporting its
>crew for the rest of their lives.
>
> It has to be a fast enough ship to get back in an acceptable amount of
>time.  To slow and theirs no practical reason to send it.
>
>
>
>---------------------------------
>Pick up and return by follow on flight
>
>>Pros
>Most of the advantages of the round trip model, and would allow the first
>ship to be a mobile research station or other specialized ship, with faster
>courier ships providing round trip flights.
>
>>cons
>High risk and more complicated.  Multiple ship types, and concerns that the
>first ship might be left stranded.
>
>
>---------------------------------
>Crew constructs equipment for return flight
>This option come up with light/microwave sail craft, beamed power craft,
>and fuel launcher craft.  The crew would  construct automated duplicates of
>the systems that launched the ship from Sol space.
>
>>Pros
>Would establish launcher facilities in both star systems.  Which could
>allowing faster two way flights with specialized fast light ships.
>
>The crew might get back faster with their ship using the constructed
>launcher systems for assistance.
>
>cons
>If they can't build the equipment, they don't get home.
>
>The construction phase may require so many resources that the first flight
>is devoted just to infrastructure construction.  With little or no
>exploration being done in the first mission.  This obviously would cool
>public interest and slow down the return of productive information.
>
>
>
>
>---------------------------------
>Multi-step.  (Ship proceeds to other target star after completion of first
>mission, in first starsystem.)
>
>>Pros
>One mission explores multiple star systems.
>
>>cons
>Technical feasibility is low since wear and tear on the ship would
>accumulate, dramatically increasing the likelihood of a catastrophic
>failure.
>
>Because of the extremely long flight times with likely technology, the
>mission would take so long as to be undesirable.  At some point the ship
>would be superseded by newer faster ships sent straight out from earth,
>decades after its launch.
>
>
>---------------------------------
>Multi-generation Succeeding generations of crew continue the mission
>
>>Pros
>This is the one of the standard concepts suggested to get around the
>extremely long flight times.
>
>Could allow extremely long flight times.
>
>cons
>The ship would have to be huge to support the active crew,
>retired/incapacitated crew, children, and all the extra support facilities
>and personnel they would require.
>
>The crew, ship, and equipment would need to be even larger than that to
>allow them to be able to completely rebuild the ship from the inside out as
>it, and its systems, exceeded their service lives.
>
>Any ship that takes that long to get to where it wants to go, will probably
>find it gets there after newer faster ships from earth.  So their is little
>reason to launch it.
>
>The flight would take so long few people would be enthusiastic in launching
>it, even if they didn't consider the likelihood of faster follow on craft.
>I.E. why spend money on something you'll never see the results of, nor even
>ever know if they made it.
>
>The follow on generation(s) in the ship will have no allegiance or
>commitment to the mission or its originators (they, never agreed to
>anything).
>
>The follow on generations would have no hands-on experience with the
>exploration systems they would be expected to use.  Or for that matter, any
>experience with planets and starsystems.
>
>Its harder to get qualified people to go on such a flight.  People who want
>to explore wouldn't want to spend the rest of their life stuck in a ship,
>knowing they will never contribute anything but their genes.
>
>
>
>---------------------------------
>Hibernation flight
>>Pros
>This is the other one of the standard concepts suggested to get around the
>extremely long flight times.
>
>The ship would not need to support the inactive crew.
>
>The crew wouldn't need to spend years of their lives waiting around in the
>ship with nothing to do until they get to the star system.
>
>The crew will still be fresh and familiar with their jobs when then are
>waken up in the star system.
>
>
>>cons
>The ship systems will still exceeded their service lives, but their may not
>be enough people around to service them.  The sleepers could wind up dying
>on route as the ship died around them.
>
>The sleepers would have to be extremely well shielded from radiation, since
>their cell repair mechanisms would be as dead as they are.
>
>Any ship that takes that long to get to where it wants to go, will probably
>find it gets there after newer faster ships from earth.
>
>The flight would take so long few people would be enthusiastic in launching it.
>
>
>
>
>
>               technical                 political          Desirability
>             Risk    Feasibility     risk     Feasibility
>-------------------------------------------------------------
>One-way      med-low  Medium         Ex-high    Nil          Low
>Round trip   medium   medium         low        High         high
>Pick-up      Med-high medium         medium     medium       medium
>Construct ret high    med-high       medium     medium       medium
>Multi-step   Ex-High. med-low        low        Medium       medium
>Multi-gen    Ex-high  Low            high       medium       low
>Hibernation  high     Low            medium     medium       low
>
>
>
>
>
>-------------------------------
>
>============================================================
>Alternatives
>---------------------------------
>robotic fly by's
>
>>Pro
>Could use a smaller lighter ship and could tolerate longer flight times.
>
>>Con
>requires extremely good A.I. systems and reliability (which may or may not
>be likely by 2050), and would generate far less public interest.
>
>Why bother, you could do nearly as well with huge telescope systems in the
>Sol star systems
>
>
>---------------------------------
>Robotic exploration
>
>>Pro
>Could use a far smaller lighter ship and could tolerate longer flight times.
>
>>Con
>Again requires extremely good A.I. systems and reliability, and would
>generate less public interest.
>
>Would be less capable than a manned mission.
>
>
>
>
>============================================================
>Mission purpose
>---------------------------------
>Colonization of planets or moons
>
>>Pro
>Very popular idea with public.
>
>Excellent staging area for direct examination of that planet or moon.
>
>>Con
>Expensive.  Either the colony would need to be the size of a major city to
>support all of the specialists needed to support a self sustaining society,
>or regular (extremely expensive) supply flights from earth would be
>necessary.
>
>On a planet with a Earth-like ecology it would be a biological death trap.
>Alien microbes, allergens, and other unknowns life forms would easily
>defeat unprepared Earth mammalian immune systems.
>
>On a planet with a non-Earth-like ecology it still could be a biological
>death trap, and in addition have basic climate and biosphere
>incompatibilities (Wrong temperatures, air pressures, gravity).
>
>Isolation from resources.  Ores, energy and raw materials are far harder to
>access on a planet than in space.
>
>Isolation from other planets.
>
>Their doesn't seem to be enough practical justification for such a massive
>undertaking.
>
>
>---------------------------------
>Colonization of constructed space platforms
>
>>Pro
>Still may be a very popular idea with public.
>
>Excellent staging area for examination of the solar system.
>
>Much lower biological threat than on a planet with biosphere.
>
>The internal gravity, radiation, and environment can be precisely tailored
>to humans.
>
>Far easier to construct and service than a planet bound colony.
>
>Easy access to plentiful resources.  (Space is considered so much richer in
>cheap, easy to access resources and power.  That it is expected that
>Earth's heavy industry will migrate into space in the next century.)
>
>Could act as a servicing center and supply port for the starship, or
>subsequent starships.
>
>
>>Con
>Expensive.  Either the colony would need to be the size of a major city to
>support all of the specialists needed to support a self sustaining society,
>or regular (extremely expensive) supply flights from earth would be
>necessary.
>
>Their doesn't seem to be enough practical justification for such a massive
>undertaking.
>
>
>
>---------------------------------
>Infrastructure construction
>
>>Pro
>This could establish facilities necessary for routine, lower cost, flights
>between home and this starsystem.
>
>>Con
>Construction could take so many resources that little or no exploration
>will be done.
>
>Less interesting to public than an exploration or colony program.
>
>Could be very expensive.
>
>
>--------------------------------------------------
>============================================================
>propulsion systems
>---------------------------------
>Fusion feed from internal fuel sources.
>
>A fusion powered rocket could cross interstellar distances, and is a near
>term enough technology to be considered likely for the mid 21st century.
>Unfortunately the amount of fuel it takes to get such a ship up to a usable
>speed (at least 1/5th of light speed is necessary.  More than a 1/3rd is
>highly desirable.) is not carryable by such a ship.  Since the fuel would
>weigh hundreds to thousands of times as much as the rest of the ship.
>
>For example for a fusion rocket with a specific impulse of 1,000,000.  If
>you wanted to use such an engine to accelerate a ship up to 1/6th the speed
>of light.  The ship would need to carry 147 times its dry weight in fuel.
>If you want to get to 1/3rd the speed of light, it would need to carry
>22,000 times its weight in fuel!  Obviously no realistic ship could do
>this.
>
>(Note: a specific impulse of 1,000,000 (A  exhaust velocity of
>10,000,000m/s) means that the engine gives 1,000,000 pounds of thrust, for
>one second, for every pound of fuel consumed.  This has long been
>considered a very do-able fusion performance number.  For comparison the
>best chemical engines have a specific impulse of 455.)
>
>---------------------------------
>Staged fusion ship
>
>You start with a 1 billion ton fueled ship cluster driven by a 10 million
>ton engine and support structure (yeah right.).  That engine is powerful
>enough to push the whole mess with an acceleration rate of 10m/s.
>
>When you burn off 95% of your weight in fuel.  The ship cluster weighs 50
>million tons, 20% of which is a first stage engine/structure that's WAY too
>powerful.  You throw the first stage away and start a smaller second stage.
>It weighs about 400,000 tons (about as much as 4 aircraft carriers) and
>can push the 40,000,000 ton ship cluster. When you burn that down to
>2,000,000 tons of cluster you throw that away that stage for a 70,000 ton
>ship with 5-10,000 tons of drive systems.  Which can use the remaining
>390,000 tons of fuel to get itself into the system.
>
>stage  total weight (tons)     thruster pack and stage structure
>1      1,000,000,000           10,000,000
>2         40,000,000              400,000
>3          2,000,000               70,000 ton ship
>                                 with 5-10,000 tons of
>                                  drive systems.
>
>This assumes a 100 to 1 thrust to weight ration for a fusion drive systems
>(which is questionable), and once you get where your going, coming back is
>out  (unless of course you scale the craft up accordingly).  But it would
>give us huge fuel ratios for relativistic flight.  So, in theory, a Multi
>stage fusion craft could get to the star.  Assuming of course you can find
>a billion tons of fusion fuel, and a ship yard in space that can construct
>a ship the size of an asteroid!  Which means in practice the ship is
>unbuildable.
>
>These numbers of course assume the ship has to carry the weight of its
>fuel.  Obviously craft normally have to carry their fuel, but their are
>some ways around it.
>
>---------------------------------
>Fusion with externally feed fuel sources
>
>A fuel launcher is a linear accelerator mounted somewhere in our solar
>system.  It throws the fuel out in front of where the ship is going to fly.
>The ship scoops up the fuel as its going along.  This has several
>advantages.  The ships engines only need to accelerate the ship itself.
>(They don't even have to adjust for changing ship weights.)  The fuel is
>accelerated up by the launcher.  This means the launcher system (who's
>power comes from unaccelerated fuel) takes up a large fraction of the load,
>and the ship saves a lot of energy.
>
>Problems are that unless the ship is flying to a starsystem with a
>operating fuel launcher.  It can't fly any faster then a speed it can
>decelerate from using its onboard fuel reserves.  Also, this only works
>when your close enough to the launcher that it can accurately launch the
>fuel to you.  Once your out of range, your stuck with fuel your caring.
>
>Fuel launchers (or beamed power) have the advantage of eliminating the need
>for the ship to carry the heavy fuel (and power systems).  That improves
>the ships power to weight ratio significantly.  But the systems are
>difficult to do, limit range, and don't seem to help us to slow down.
>
>
>
>Beamed power
>
>Beamed power (or fuel launchers) have the advantage of eliminating the need
>for the ship to carry the heavy fuel (and power systems).  That improves
>the ships power to weight ratio significantly.  But the systems are
>difficult to do, limit range, and don't seem to help us to slow down.
>
>Beamed power systems are most effective as microwave sail craft.  But
>powered electromagnetic drives are possible also.
>
>
>Anti-matter
>Can be destroyed to create tremendous amounts of energy.  Releases over a
>hundred times as much power per pound of fuel as a fusion reaction.
>
>Unfortunately, though it releases more power, this power is harder to
>directly use to power the ship.  It is however far more dangerous to
>handle.  If we could synthesize the thousands of tons of antimatter this
>would take.  It would have the potential of exploding with a force of
>hundreds of millions of H-bombs.
>
>We do not have the technology needed to synthesis,  store, or ship
>anti-matter on this scale, and are not likely to get it by 2050.
>
>Ramscoop
>
>This idea would allow a ship to scoop up interstellar hydrogen and use it
>for fuel.  Like a fuel launcher system it could accelerate to high speeds
>without concern for high fuel to weight ratio's.
>
>Unfortunately we don't really know what's in interstellar space, but we do
>know we are in a very thin part of it due to a recent supernova in the
>area.  We might need a scoop thousands of kilometers across for a decent
>sized ship.
>
>We also know that straight hydrogen is very hard to fuse, and doesn't fuse
>as quickly as we might need.
>
>All in all we have no real idea on how to make such a ship work.
>
>
>
>Future tech
>
>The engineering and science we have now and assume we will have in the
>future will change.  Fusion, fission, relativity, quantum mechanics, and a
>host of other basics of current physics; all were discovered within the
>last hundred years.  We can conservatively expect physics to have changed
>far more in the next hundred years, then it did in the last hundred years.
>What technologies that age will have on hand are impossible to guess.  They
>could have matter conversion, hyperlight drives, new understandings of
>inertia and kinetic energy, or all those and far more.  Any of these would
>dramatically effect our ability to travel between the stars.  So even
>though we can't come up with any practical ideas for exploring the stars
>now, we can be sure our descendants will find it far easier than we
>imagine.
>
>Kelly Starks
>
>
>
>----------------------------------------------------------------------
>
>Kelly Starks                       Internet: kgstar@most.fw.hac.com
>Sr. Systems Engineer
>Magnavox Electronic Systems Company
>(Magnavox URL: http://www.fw.hac.com/external.html)
>
>----------------------------------------------------------------------


----------------------------------------------------------------------

Kelly Starks                       Internet: kgstar@most.fw.hac.com
Sr. Systems Engineer
Magnavox Electronic Systems Company
(Magnavox URL: http://www.fw.hac.com/external.html)

----------------------------------------------------------------------