Message-ID: <8ZLGUVW00VcJMWV052@andrew.cmu.edu>
Reply-To: space+@Andrew.CMU.EDU
From: space-request+@Andrew.CMU.EDU
To: space+@Andrew.CMU.EDU
Date: Sun, 12 Nov 89 03:21:54 -0500 (EST)
Subject: SPACE Digest V10 #238

SPACE Digest                                     Volume 10 : Issue 238

Today's Topics:
		      Re: Future Space Missions
		    Re: Moon Colonies / Ant Tanks?
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Date: 12 Nov 89 05:55:44 GMT
From: bfmny0!tneff@uunet.uu.net  (Tom Neff)
Subject: Re: Future Space Missions

In article <1989Nov12.001720.6482@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>The only available-now launcher that could do a better job on Cassini
>would be Energia.  The Soviets have no superstitious fear of cryogenic
>upper stages ...

Whoa, neither do we, if we're talking upper stages on unmanned
boosters.  The knock on Shuttle/Centaur was taking that cryogenic upper
stage up on the flatbed of a human crewed truck!  It was the astronaut
office, not armchair critics, that nicknamed it the "Death Star".  Who
got it cancelled?  A couple of guys named Young and Crippen...

Let's take bets on how eager the Soviets would be to take a Centaur up
inside Buran.  Of course THEY could do it unmanned anyway.  And of course
THEY don't even need to since they have plenty of booster power.
-- 
"UNIX should be used          ::   Tom Neff <tneff@bfmny0.UU.NET> or
 as an adjective." -- AT&T   ::    ...uunet!bfmny0!tneff (UUCP only)

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Date: 12 Nov 89 07:26:57 GMT
From: mentor.cc.purdue.edu!f3w@purdue.edu  (Mark Gellis)
Subject: Re: Moon Colonies / Ant Tanks?

I've been reading the discussion of space colonies with some interest
since I, like some of you, write sf (in my spare time).  Of course, I
tend to like stories set in the relatively far future, and my vision of
space colonies is much more optimistic than what I've heard from a lot
of people.

I assume a few things.  Cheap solar and fusion power.  Raw materials that
can be used in the asteroids, and both the atmospheres and moons of gas 
giants.  Fairly intelligent robots.  Self-replicating machinery.  The
first space colonies will be more like mining and manufacturing outposts,
naturally, but after a century or two, when various technologies have been
perfected, I would be VERY surprised if space colonies are not fairly roomy
places.

My basic model is a 15 km. x 60 km. cylinder, spun for gravity, using
solar or fusion power for energy.  If it is close enough to the sun, about
half of the cylinder is "sky window"; otherwise, you use holographic panels
and fiber optics and a lot of power (which is cheap if you have cheap fusion
power) to create an artificial sky.  Surface area of the landscaped interior
(or "dayside") is about 1200 square km.

At each end of the cylinder you have one hundred meter wide sections that
are closed off and structured into levels.  If you use ten-meter high levels
(the idea is to make this place roomy, as much like an outdoor planet as
possible), giving the ceilings holograph panels that create a sky-illusion,
you can have more than seven hundred levels on this thing.  Both "endwall
complexes" will thus have a surface area of about 3000 square km. (total
for both).  Total surface area of enclosed levels and landscaped dayside
is more than four thousand square km. (about the size of Rhode Island--
actually, somewhat larger than Rhode Island).

Population (optimal): 1,000,000 persons.  Population density: about 250 
people per square km.  (roughly the same as the United Kingdom)

Ant hills?  Only for the first space colonies.  When it becomes cheap
to build them (as inexpensive energy, intelligent machines, and self-
replicating machines will help make it), people will find a somewhat more
roomy design preferable to "maximum survivable density."  They will
want parks, even wilderness, they will want diversity, open spaces, and
places where they can be isolated and in touch with life.  (I am also
a firm believer that societies where people are (a) cut off from contact
with a diversity of natural life forms and/or (b) forced into cramped
conditions too often become VERY unhealthy.  I learned this from my
experience in commuting to and working in New York for about two years.
If the world ends up like New York, we won't have to worry about space
colony designs because we will never make it there in the first place.  
In fact, I only think space colonies are a good idea because I see the
potential to build them as small, artificial planets, as "microworlds"
rather than "apartment buildings in space."  I don't think societies
without ecologies are a very good idea; I suspect they will be very
(and rapidly) self-destructive.  Of course, at the same time, I don't
think total isolation is very good for societies either.  Perhaps I
am being arbitrary, but I have a feeling that one million people, close
enough so that anyone can invite anyone else to dinner and have them in
their home in an hour, but big enough enough to be totally alone if they
want, is a good safe balance between natural wilderness and sophisticated
civilization.)

Enjoy.

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End of SPACE Digest V10 #238
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