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Date: Sun, 18 Feb 90 01:56:53 -0500 (EST)
Subject: SPACE Digest V11 #59

SPACE Digest                                      Volume 11 : Issue 59

Today's Topics:
            Re: Why we need Earth
           Re: Why we would need a planet.
             HST damage in orbit
                 GIF pictures
            Re: Galileo Update - 02/12/90
           Re: Why we would need a planet.
      Re: Fun Space Fact #1: Launcher Development Costs
           Re: Why we would need a planet.
      Re: Fun Space Fact #1: Launcher Development Costs
----------------------------------------------------------------------

Date: 17 Feb 90 06:37:41 GMT
From: zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!uniwa!vaxa![e-mail]  (Gunter Ahrendt)
Subject: Re: Why we need Earth


    paul dietz:
>Why?  Planets are a terribly inefficient way to use mass.  All that
>inaccessible matter just to provide gravity, when rotating structures
>(of sufficiently large size) would do just as well, using much
>less material.

Inefficient way to use mass? I don't see how anyone is qualified to judge
nature in the ways you do. Otherwise you should consider the human race to be
the most overly inefficient use of life nature has come up with.

>Why can't future generations do so, if they find the existence of
>Earth serves no useful purpose?

Raping the Earth then going of elsewhere to ultimatly do the same shows no
consideration whatsoever for the countless other varieties of life that inhabit
them (Earth anyway). This is just the kind of selfish atitude that has brought
the world environmentaly to the state it is currently in.

Everything serves a purpose, if you think something doesn't that in no way
gives you the right to destroy it.

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

Date: 17 Feb 90 23:17:40 GMT
From: thorin!homer![e-mail]  (Jonathan Leech)
Subject: Re: Why we would need a planet.

In article <[e-mail]> [e-mail] (Peter Scott) writes:
>Jeez, look what you could do by crashing two Galilean moons together :-)

    Depending on how much heat was dissipated, perhaps make the
galaxy's biggest sulfur-flavored Slurpee?
--
    Jon Leech ([e-mail])    __@/
    "The satellite was one of seven launched yesterday by the Soviets."
    - BBC News

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

Date: 18 Feb 90 04:17:58 GMT
From: frooz!cfashap![e-mail]  (Bill Wyatt)
Subject: HST damage in orbit

[I'm posting this to get a wider response to the question -
send any e-mail to the address below - WFW ]

From: tmsoft![e-mail] (Leigh Clayton)

 (you may repost this or not as you choose; I don't have a true news poster
right now).

 There was an interesting article on ablation by atomic oxygen in Earth orbit
in a recent Scientific American. The corrosion rates they mentioned made HST
look *extremely* vulnerable - has this been considered in the HST design, and
if so what has been done to combat it? (I can't believe that something well
enough known to get into Sci. Am. wouldn't have been considered by the HST
team, but I've never heard the topic mentioned)

../Leigh

-----------------------------------------------------------
- Men argue, Nature acts                       /Voltaire  -
-                                                         -
- ...for we never know what is enough,                    -
- until we know what is more than enough.      /Blake     -
-----------------------------------------------------------
  Leigh Clayton,                        [e-mail]

>NOT the address below!
Bill Wyatt, Smithsonian Astrophysical Observatory  (Cambridge, MA, USA)
    UUCP :  {husc6,cmcl2,mit-eddie}!harvard!cfa!wyatt
 Internet:   [e-mail]
     SPAN:   cfa::wyatt                 BITNET: wyatt@cfa

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

Date:         Sat, 17 Feb 90 08:49:01 PLT
From: Wayne Fellows <[e-mail]>
Subject:      GIF pictures

I'm interested in finding out if there are any official BBSs where one can down
load GIF files from various probes.  Also, I'm new to the list and does anyone
have any news on the SCAMJET engine?  Has there been any appreciable progress i
n either gaining funding or in the engineering itself?

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

Date: 17 Feb 90 00:28:41 GMT
From: usc!brutus.cs.uiuc.edu!uakari.primate.wisc.edu!aplcen!haven!uvaarpa!hudson!astsun.astro.Virginia.EDU![e-mail]  (Greg S. Hennessy)
Subject: Re: Galileo Update - 02/12/90

In article <[e-mail]>
[e-mail] (Shawn E. Koppenhoefer) writes:

#Is there any way to get access to the RAW data or are we stuck
#with only the 'results' of the imaging teams? (not that they don't do
#a good job... )

Nasa  distributes CD-ROM disks with the RAW images, and the software
to process the data. The CD-ROMS are sold basically at cost.

-Greg Hennessy, University of Virginia
 USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
 Internet:      [e-mail]
 UUCP:        ...!uunet!virginia!gsh7w

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

Date: 18 Feb 90 00:29:15 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: Why we would need a planet.

In article <[e-mail]> [e-mail] (Paul Dietz) writes:
>(1) Ok, our future civilization has used the asteroids, the moons of the
>solar system, Pluto, Mercury, Mars and Venus.  At that point Earth is next.

Sounds like a rain forest argument to me!

You know how expansions go.  If we have used up all the above, adding
Earth to the list will probably buy us another couple of centuries,
tops.  Clearly something else would have to be found.  I mean, just
extend your list:

(1a) Ok, our future civilization has used the asteroids, the moons of
the solar system, Pluto, Mercury, Mars, Venus and Earth.  At that point
what do we do?

Wait, don't tell me -- let me guess -- NOW we expand to other stars, right?
Well, fooey -- if we can do it, do it before trashing Earth.  We have no
right to destroy it until we understand it well enough to make a new one.

>(2) If they are human, future civilizations may still have wars.  The
>Earth will be very vulnerable.  All it takes is one minor war with
>29th century weapons to convert Earth from prime real estate to a
>sterile graveyard.

This is lame, but EVEN so, at least wait until AFTER the war!  Presumably
a war-wasted planet would be no less suitable for the gargantuan business
of planet-busting than what we have now.  (Ain't gonna be worse than Venus,
for instance.)

>(3) It is cheaper to maintain Earth than to disassemble it, but the
>habitable surface you could produce by disassembly would be greater.
>A future civilization running up against the resource limits of the
>solar system might find disassembly worthwhile.

See expansion argument above.  I simply cannot believe that we'd know
how to bust and rearrange planets but not how to do other stuff like
steal from Jupiter or the Sun or the Oort cloud.

Anyway I remember from my old Asimov that asteroids alone reshaped flat
into Dyson type structures would house ZILLIONS.  Assuming we want
zillions.  I have my doubts about the survival chances of any system
housing zillions. :-)
--
Psychoanalysis is the mental illness   \\\    Tom Neff
it purports to cure. -- Karl Kraus      \\\   [e-mail]

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

Date: 18 Feb 90 04:09:37 GMT
From: zaphod.mps.ohio-state.edu!samsung!cs.utexas.edu!jarvis.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Fun Space Fact #1: Launcher Development Costs

In article <[e-mail]> [e-mail] (Constitutional rights? We don't need no stinking Constitutional rights!) writes:
>This shows a couple of interesting modes of thought.  First, of
>course, is the contention that the Shuttle "doesn't work very well".
>What this really means, of course, is that the Shuttle isn't what it
>was billed as when the money for it was justified to Congress.  But
>then, it was Congress that kept cutting back the funding for it,
>wasn't it?

Uncomfortable though it makes me to agree with Jim Bowery :-), he's right
on this one.  If NASA had been given every cent it wanted, the shuttle
would still not be able to meet the schedule or cost promises -- it is
far too manpower-intensive, and the facilities simply are not adequate
for the degree of parallelism that would be needed to overcome that.
That is, it simply takes too much work to get an orbiter ready for a
new launch.  And you can't overcome it by just buying a pile of orbiters
and enough manpower to process them in parallel, because there aren't
enough pads or VAB bays for that mass processing.

>The other interesting thing to be gleaned from Mr. Bowery's
>statement is that for some reason, totally undocumented and
>unsubstantiated, AMROC's booster is "likely to work very well".
>Why?  Other than the fact that it's a lot less complex and has a lot
>less capability than the Shuttle...

Modest goals and simple hardware really do go a very long way towards
making things work well.  I confess I do have a few doubts about Amroc's
hybrid rockets, but that aside, they've done the right thing.

> [lots of light boosters]
>Which is great if your goal is to put payloads ranging from a couple
>hundered to a couple thousand pounds in LEO, but hardly what is
>needed for more ambitious undertakings...

Sure about that?  The laser-launcher people say that the largest payload
which absolutely has to go up in one piece is a human with life support.
That can be done with a couple of thousand pounds, possibly rather less.

Of course, then you need on-orbit assembly, but that may be a blessing
in disguise.  Fairchild's old Leasecraft project study concluded that
putting things together in orbit is cheaper than putting them together
on the ground, because if you put them together on the ground you have
to be *certain* they won't shake apart on the way up.

Besides, none of the more ambitious undertakings now being thought about
can be done without on-orbit assembly or the equivalent anyway.

>Let us also keep in mind that AMROC is starting with a somewhat
>different technology and engineering base in place than was the case
>when the Shuttle system was originally engineered...

How so?  I don't see anything much Amroc is doing that couldn't have
been done when the shuttle was designed.  (Remember that launch technology
has been largely stagnant ever since NASA stopped funding for all
launch-technology work not related to the shuttle.)  They've got slightly
better materials and somewhat better electronics, and that's about it.
--
"The N in NFS stands for Not, |     Henry Spencer at U of Toronto Zoology
or Need, or perhaps Nightmare"| uunet!attcan!utzoo!henry [e-mail]

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

Date: 17 Feb 90 22:43:35 GMT
From: zaphod.mps.ohio-state.edu!sunybcs!uhura.cc.rochester.edu!rochester![e-mail]  (Paul Dietz)
Subject: Re: Why we would need a planet.

In article <[e-mail]> [e-mail] (Peter Scott) writes:
>  And then there's
>economic reasons.  It would be far cheaper to maintain the Earth as a viable
>habitat for human beings than to cannibalize it to make some other habitat.
>If you want to build another place to live, there are surely better choices
>than this planet for raw material.  Jeez, look what you could do by crashing
>two Galilean moons together :-)

Three comments:

(1) Ok, our future civilization has used the asteroids, the moons of the
solar system, Pluto, Mercury, Mars and Venus.  At that point Earth is next.

(2) If they are human, future civilizations may still have wars.  The
Earth will be very vulnerable.  All it takes is one minor war with
29th century weapons to convert Earth from prime real estate to a
sterile graveyard.  A spacebased civilization would not have the
disincentive that this would screw up the biosphere supporting them.
So, under this scenario, I can't see preserving the Earth as an
attainable long term goal.

(3) It is cheaper to maintain Earth than to disassemble it, but the
habitable surface you could produce by disassembly would be greater.
A future civilization running up against the resource limits of the
solar system might find disassembly worthwhile.

    Paul F. Dietz
    [e-mail]

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

Date: Fri, 16 Feb 90 15:41:25 CST
From: [e-mail] (Constitutional rights? We don't need no stinking Constitutional rights!)
Subject: Re: Fun Space Fact #1: Launcher Development Costs

Inclusions preceded by >> are by Jim Bowery.


>> The Shuttle cost around $(1990)30 Billion to develop and it
>> doesn't work very well.
>>
>> The American Rocket Company (AMROC) cost about $(1990)30 Million
>> to start up and it developed a launcher that is likely to work
>> very well.

This shows a couple of interesting modes of thought.  First, of
course, is the contention that the Shuttle "doesn't work very well".
What this really means, of course, is that the Shuttle isn't what it
was billed as when the money for it was justified to Congress.  But
then, it was Congress that kept cutting back the funding for it,
wasn't it?

The other interesting thing to be gleaned from Mr. Bowery's
statement is that for some reason, totally undocumented and
unsubstantiated, AMROC's booster is "likely to work very well".

Why?  Other than the fact that it's a lot less complex and has a lot
less capability than the Shuttle, on what is the contention that
it's "likely to work very well" based, other than Mr. Bowery's
politics?


>> That's a factor of ONE THOUSAND less.

>> I wonder what would happen if you just passed out one thousand
>> chunks of money at $30 million a crack to anyone who looked
>> vaguely like they had an idea about how to build a better launcher
>> (and, of course, kept them away from metropolitan areas :-).

I think that Mr.  Bowery shows his understanding just what should be
expected if such a course were followed.  One could expect about $27
billion worth of pyrotechnic displays.  Of the remaining 10%, there
would be about 90% running out of money due to technical problems but
which involved some worthwhile gain in technology.  And of the
remainder, there would be from half a dozen to a dozen new LIGHT
boosters.

Which is great if your goal is to put payloads ranging from a couple
hundered to a couple thousand pounds in LEO, but hardly what is
needed for more ambitious undertakings.  The scattergun approach is
usually not particularly fruitful when a specific requirement is to
be met.

Let us also keep in mind that AMROC is starting with a somewhat
different technology and engineering base in place than was the case
when the Shuttle system was originally engineered.  One cannot
simply adjust the dollars spent for time and assume that that makes
all else equal.

I realize that keeping in mind factors such as payload, mission, and
technological development already in place don't make for nearly as
much satisfaction as a nice, politically oriented flame, but then I
find that Mr. Bowery's comments in general usually contain entirely
too much heat and too little light.

And that's really a pity.  On those rare occassions when he can
refrain from bashing The Great Satans of Scott Pace and NASA and
from postulating that anyone who disagrees with him is the victim of
some mental deficiency and has thus been taken in by "The Big Lie",
he posts some relatively interesting and inciteful pieces.

Unfortunately, those occassions are all too rare, and even those few
well reasoned and explained articles get little weight given to
them, given a readership which has trudged through all the bombast and
political diatribe with which Mr. Bowery usually loads his postings.


>> ---
>> Typical RESEARCH grant:
>> $
>> Typical DEVELOPMENT contract:
>> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

Lesson?  That actually DOING something costs much more than merely
THINKING about it.  Is this really such a surprise to Mr. Bowery,
and does he seriously expect any of us to be as amazed and horrified
at it as he seems to be?


==============================================================================
| Fred McCall  ([e-mail]) | My boss doesn't agree with anything  |
| Military Computer Systems           | I say, so I don't think the company  |
| Defense Systems & Electronics Group | does, either.  That must mean I'm    |
| Texas Instruments, Inc.             | stuck with any opinions stated here. |
==============================================================================

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

End of SPACE Digest V11 #59
*******************