Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_5/V13_552.TXT

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Subject: SPACE Digest V13 #552

SPACE Digest                                     Volume 13 : Issue 552

Today's Topics:
            SPACE Digest V13 #516
              Re: Honking at cyclists...
           Re: LIFE article on Mars Terraformation
              Re: Why the space station?
         Re: Laser launchers (really tethers)

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ReSent-Message-ID: <Added.Qc=[e-mail]>
Resent-Date:  Mon, 13 May 91 12:57:07 EDT
Resent-From: Tom <[e-mail]>
Resent-To: [e-mail]
Date:         Fri, 10 May 91 01:52:48 EDT
Reply-To: [e-mail]
From: [e-mail]
Subject:      SPACE Digest V13 #516
Comments: To: [e-mail]
To: david polito <[e-mail]>, Tom McWilliams <[e-mail]>

>Re: Galileo flyby of ateroids.

{stuff deleted regarding the various good/bad reasons/lack of reasons for
  dropping Jupiter for The 'Stroids (if it's broke)}

(we could send Gailieo to get data from 'Stroids)
>Only if you are going to get some valuable data in the process.  Below, you
>mention that the only data we have on asteroids is spectroscopic.  What do
>you think you are going to get from Galileo?  It doesn't have any way of

Except that the limitation from Earth is angular resolution.  That would be
the improvement that would make it worth while.

>>We will never study the interior
>>of any of Jupiter's moons, let alone Jupiter.

>How do you know that?  There is absolutely no reason we cannot study the
>interior of Jupiters moons, in a manner similar to how we have studied the
>interior of Earth.  Jupiter is a bit of a trick, but since we don't have
>*any* solid (non-theoretical) information on the composition of Jupiter
>below the cloudtops, any information we can get will be a bonanza compared
>to what we have now.

Point taken, but it still stands that only with the 'stroids can we
>>recover all the heavy metals (i.e. gold, iron, lead, copper)
>>that are forever hidden at the center of the other planets.

>We are a *long* ways from this kind of space exploitation; waiting an extra
>ten or twelve years to get the data won't make any real difference in our
>schedule of space exploitation.

>>And finding those heavy metals could be the incentive that private industry
>>needs to get their butts busy building a space infrastructure.

>Again, we are a *long* ways from this stage.  Scrapping a valuable Jupiter
>mission to gain a few years in getting some poor data (remember, you're not
>going to find out what is at the core of these asteriods with Galileo) on a
>few asteroids isn't going to get private industry out there any sooner.
>They'll still have to wait on a penetrator mission at the very least, which
>may well be delayed by sending Galileo to asteroids.

Agreed, a penetrator mission would be better.

Disagree that we are a long way from industrial activity ('no matter what')
Disagreed that Galileo would waste it's time on the Asteroids.

Many times, the people on this list have extolled Private Industry for it's
ability to cut costs, deliver on contracts, etc, etc that Gov. just can't
deliver.  So how do we get PI to pick up where NASA fumbled?  By showing
how payoff makes the risks worth it.  Knowledge, even fragmentary, of
the Asteroids could be that demonstration.

If NASA, a gov agency, could get guys on the moon, in ten years, with
National Prestige/Fear the motivation, think what PI could do, with
Big $$ as the motivation.  Especially with the experince we have now.

Japan went, in 40 years, from a nuked island to a world industrial power,
arguably the most powerful, with $$ as the motivation.

Conclusion; yes, it could significantly alter the timetable for space
development / commercialization.

>Sure.  But junking Galileo won't accelerate the process, so why bother?

See above.

>If it's not going to make a good probe, then it's not worth diverting it from
>a mission it was designed to do.

What's your measure of 'good'?  You mean 'best'?  I mean 'good enough'.
My point, which I hardly expect anyone else to share, is that Jupiter can
take a flying f__k at a rolling donught, (IMHO).  The 'stroids are a much
better resource.  And if our concern is resources, we should do something
to find them (or find the lack of them).

Galileo would be good enough to tell us if the 'stroids are a resource or
not.  I feel that information is more important than ANYTHING we could
learn about the Jove's.

>>especially if a mal-function meant that we'd get a lousy view
>>of Jupiter's moons, too.

>We already have lousy views of asteroids...why do we need *more* lousy
>views?  And, as has been said before, we're going to get some more lousy
>views *anyway*, plus Jupiter data.

See above about advantages of galieo for finding new info about 'stroids

>One thing that I didn't mention above, and that you seem to have forgotten,
>is that CRAF (Comet Rendezvous and Asteroid Flyby) is in the planning
>stages now; it'll get more data from asteroids than Galileo will, by a
>long shot.

I'll cross my fingers that it gets out of the planning stages.

Tommy Mac
Acknowledge-To: <18084TM@MSU>

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

Date: 14 May 91 03:38:05 GMT
From: cis.ohio-state.edu!zaphod.mps.ohio-state.edu!samsung!rex!rouge![e-mail]  (Fraering Philip)
Subject: Re: Honking at cyclists...


After reading this whole thread, I've come under the conclusion
that the whole lot of you, debating how much of the universe
should (or could) be chewed up for industrial development, have
gone Crazy Eddie.
--
Phil Fraering || Usenet (?):[e-mail] || YellNet: 318/365-5418
''It hardly mattered now; it was, in fact, a fine and enviable
madness, this delusion that all questions have answers, and nothing is
beyond the reach of a strong left arm.`` - Larry Niven and Jerry
Pournelle, _The Mote in God's Eye_

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

Date: 13 May 91 07:03:08 GMT
From: sequent!muncher.sequent.com![e-mail]
Subject: Re: LIFE article on Mars Terraformation

In article <[e-mail]> [e-mail] (Frank Lalonde) writes:

>I recently read an article on the Terraformation of Mars in the May 1991 issue
>of LIFE magazine. I would like to know how realistic or accurate this article
>was from those of you who might have read the article and have some expertise
>in the field.

Technologically, it looked straightforward.  Use several methods,
primarily solar thermal energy from mylar mirrors (thousands of times
cheaper than solar electric energy in space), to free up the water and other
volatiles locked up in the polar caps and underneath the Martian surface.
Atmosphere forms with CO2 and increasingly N.  Start introducing plants.
Break up FeOx into refined iron and oxygen.  After c. 80 years pressure
is enough to swap space suites for oxygen masks; after c. 150 years
we can drop the masks and breath oxygen.

The cost estimates seemed to be pulled out of the blue.  Crude calculations
showed they were assuming launch costs 1,000 times lower than at present.
The main source of revenue seemed to be real estate sales.  If so, the
project was heavily subsidized, since costs a factor of 50 higher than
current Earth undeveloped real estate costs would be required to pay back
the project price.  The other industries they discussed amounted to vague
notions of Mars becoming a "hi-tech" center.  There is nothing for these
industries unique to Mars; they could just as easily sprout up in Venezuala
or Antartica or the Moon.

There is plenty to be said for microgravity and vacuum environments
for industry, but those must be located in free space, and the best
e best sources of materials are comets and asteroids.

A similar, more realistic Martian scenario, but with less rapid immigration,
could occur from launch costs 100 times lower than present combined with
a mature space manfucturing capability based on asteroid, comet, and/or
lunar materials delivering mirrors and other heavy equipment for 100,000
times less cost than if launched from earth at today's costs.  In this
case, terraformed real estate would sell well unsubsidized.  Mars would
basically become a large, sparsely populated nature park, and those folks
most in love with uncrowded nature would be the first major buyers of
Martian real estate.

Earlier than this, mining facilities (primarily or entirely automated
at first) might provide the first self-sustaining infrastructure on
the Red Planet.  The early geological processes on Earth, up until the
time oxygen entered our atmosphere, all existed on Mars: surface water,
volcanism, etc.  Furthermore, the Martian surface is relatively richer in
heavier core elements, such as nickel, iron, and platinum-group metals,
due to Mars' lower gravity.  Therefore, if we are lucky we may find large
concentrations of precious metals.  For example, portions of the large
alluvial fans we see might have sections full of gold flakes, similar to
the secondary alluvial gold deposits that started the California and other
gold rushes.

There is a good article in this month's Scientific American that
describes the processes that went into forming the iron, nickel,
copper, gold, platinum, etc. deposits on earth.  Some of these will
occur in some parts of space; many won't.

There may very well be other processes at work in space that don't occur
on Earth.  Two that come to mind right away are the collision processes
in the asteroid belt that exposes core materials (refined nickel-iron with
larger concentrations of platinum-group elements) and create diamond
from the shock of impact with carbon-rich materials at 5 kilometers/second.
We know the core metal is very common; we don't know yet the location or
volume of the asteroids that parent the ureliete diamond meteors on
Earth.

I keep wondering what effect Jupiter's large magnetic field would
have on Io's ore-forming processes.  The large electric potential might
cause some macro form of electrophoresis.  Sulfides are the primary carrier
of ores on Earth anyway.  Should be interesting.  I hope Galileo makes
it.

Well, I strayed a bit from the original subject there. :-)  I conclude
that Mars is promising, as are many, many other places in the solar system.



--
Nick Szabo                [e-mail]
"If you understand something the first time you see it, you probably
knew it already.  The more bewildered you are, the more successful
the mission was." -- Ed Stone, Voyager space explorer

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

Date: 13 May 91 18:51:46 GMT
From: mintaka!ogicse!sequent!muncher.sequent.com![e-mail]
Subject: Re: Why the space station?

In article <[e-mail]> [e-mail] (Henry Spencer) writes:

>The smaller probes definitely don't need assembly.  The bigger ones really
>could use it.  Just look at some of the elaborate schemes people have put
>together trying to do a Mars sample return using existing launchers with
>no in-space assembly.  Those plans are far riskier and far more exotic than
>putting the mission together in orbit.

Care to expand on this?  I fail to see how in-orbit assembly makes
a sample return, from Mars or other places, any easier.

Note that both the Soviet Union and the U.S. did extensive sample
return from the Moon without in-orbit assembly.



--
Nick Szabo                [e-mail]
"If you understand something the first time you see it, you probably
knew it already.  The more bewildered you are, the more successful
the mission was." -- Ed Stone, Voyager space explorer

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

Date: 13 May 91 21:23:56 GMT
From: mintaka!ogicse!sequent!muncher.sequent.com![e-mail]
Subject: Re: Laser launchers (really tethers)

In article <[e-mail]> [e-mail] (Gary Coffman) writes:

>Yep, I knew that Mike. I was assuming from the context of previous
>postings that Nick was referring to beanstalks since we were talking
>about the cost to orbit and most of that cost is in the lowest levels
>of flight where dynamic tethers seem impractical due to atmospheric
>drag.

The cost of an above atmosphere, sub-orbital launch is about 1/4
the cost of an orbital launch, and a suborbital launch doesn't
have to provide _any_ orbital energy, so it is not true that
"most of the cost is at the lowest levels of flight."  A tether
system would consist of a suborbital rocket, gun, or airplane,
and a tether, entirely in vacuum,  which provides all of the orbital
velocity.  There is also a scheme Keith Henson proposed whereby a
tether based on an airplane could whipsaw significant payloads
the the atmosphere, where they would be picked up by the vacuum-based
orbiting tether.

There are so many unexplored possibilites here.  Instead of
covering the same old scoured ground, let's start digging up
some fresh territory.  It's not much use being last in line at
the Easter Egg hunt.


--
Nick Szabo                [e-mail]
"If you understand something the first time you see it, you probably
knew it already.  The more bewildered you are, the more successful
the mission was." -- Ed Stone, Voyager space explorer

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

End of SPACE Digest V13 #552
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