Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_0/V15NO051.TXT

Internet Message Format | 1993-07-13 | 34KB

Date: Thu, 30 Jul 92 05:02:21
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #051
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu, 30 Jul 92       Volume 15 : Issue 051

Today's Topics:
        Astronomy Lab for MS Windows 3.X - BETA TESTERS NEEDED
                         Calendar and Zodiac
                          Canadian comments
                        Clinton Space Position
                        ETs and Radio (7 msgs)
                          Glaciation on Mars
                           Happy Birthday!
                            Soyuz as ACRV
               Space Station Freedom assembly questions

    Welcome to the Space Digest!!  Please send your messages to
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    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: 22 Jul 92 12:37:23 GMT
From: Per Baekgaard <[e-mail]>
Subject: Astronomy Lab for MS Windows 3.X - BETA TESTERS NEEDED
Newsgroups: comp.windows.ms,comp.ibm.pc.misc,sci.astro,sci.space,sci.edu,comp.windows.ms.programmer,comp.binaries.ibm.pc.d

[e-mail] (Eric Bergman-Terrell) writes:


Sorry once again...

I'd like to be a beta-tester, too. Here's the info:

    Name: Per Baekgaard
    US Mail Address: PTS, Koegevej 62, 1., DK-2630 Taastrup, Denmark
    E-Mail Address: [e-mail]
    Version of MS-Windows: 5.0
    Version of MS-DOS: 3.1
    CPU: 486/33 MHz
    Math Coprocessor (not required): (part of the CPU)
    Memory: 16 MB
    Graphics Card: Prisma Full House VGAMAX 1024 (VESA compat.)
    Printer: QMS-410 Postscript printer


Regards,


-- Per.

--
Per Baekgaard, Pine Tree Systems, Denmark
email: [e-mail]   or   ...!mcsun!dkuug!pine!peb

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

Date: Wed, 29 Jul 1992 20:10:07 GMT
From: Ken Arromdee <[e-mail]>
Subject: Calendar and Zodiac
Newsgroups: sci.space,alt.folklore.urban

In article <[e-mail]> [e-mail] (John Roberts) writes:
>In the British Empire, the month of September, 1752 lost 11 days (the day
>after September 2 was September 14). It was the renters who complained,
>because they had to pay a full month's rent.
>
>The months themselves have been around for thousands of years.

OK.  I've had it.  Could someone in alt.folklore.urban please clear this up?

The way I've usually heard this is as a "rebuttal" to the notion of
superstitious peasants who felt that they lost 11 days out of their life
because of the calendar change; the explanation, you see, is that they were
upset about having to pay the extra 11 days rent, so they weren't acting on
superstition at all.

But even this seems rather suspicious to me.  It implies a bit too much of a
lack of common sense on the part of landlords.  Does anyone know if this is
what _really_ happened?
--
Hi! Ani mutacia shel virus .signature. Ha`atek oti letoch .signature shelcha!

Ken Arromdee (UUCP: ....!jhunix!arromdee; BITNET: arromdee@jhuvm;
     INTERNET: [e-mail])

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

Date: 29 Jul 92 18:35:25 GMT
From: Derek Kirkland <[e-mail]>
Subject: Canadian comments
Newsgroups: sci.space

If Canadians are not supposed to have comments on internal US politics,
why do the major US networks hire lots of Canadians as their main
news program anchors. These Canadians are allowed to make lots of comments on US
politics and no one seems to complain.


The whole idea that "foreigners" should not comment on internal US
politics is the most ridiculous statement I have heard in years.

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

Date: Wed, 29 Jul 92 09:09:40 CST
From: Michael Ellis <[e-mail]>
Subject: Clinton Space Position
Newsgroups: sci.space

[e-mail] (Doug Davey) writes:

> Henry, your technical postings are probably the best things in sci.space.*.
> However, I would respectfully ask that those who neither pay the taxes
> nor vote in the elections kindly refrain from posting politcal analyses
> of political statements from the USAian election campaign.  If you have a
> technical reason why something a candidate proposes is a good or bad idea,
> fine.  However, a cross border political analysis is rude at best.  Thanks.
> Stop Canadian Imperialism!  Yankee Go Home! :-)
>
> --
> +--------------------------------------------------------------------+
>   Doug Davey        [e-mail]         bcr!iscp!ddavey
>


 I think you'll find that most Canadains that keep up at all on world
events are very well versed on the American campaign. Furthermore, I ask
you if you made no comments on the effects of the political coup in the
former U.S.S.R. on space developements.
 I take a great deal of interest in the campaign, as all Canadians
should. After all 90% of us live within 2 hours of the boarder, the USA
is our largest trading partner by far, and our economy is intertwined
with it's.
 If you think that a cross border political analysis is rude, then
imagine my chagrin(spelling?) when I learned that American presidents
send there campaign staffs and advisers to Canada to help the Canadian
priministereal canadate of there preference get into power.
 I think that when the most influencial power in the world's leader
starts using phrases like "NEW WORLD ORDER" you can't blame us aliens for
taking part in pre-election talks.

 Also, allow me to remind you that this is an _international_ newsgroup
and I think anything brought up here is free for all to comment on.

Stop Candada Bashing!! End political protectionism!! ;-)

ME

;--- (Michael Ellis) a user of sys6626, running waffle 1.64
;E-mail: [e-mail]
;system 6626: 63 point west drive, winnipeg manitoba canada R3T 5G8

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

Date: 29 Jul 92 16:29:09 GMT
From: Gary Coffman <ke4zv!gary>
Subject: ETs and Radio
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (russell wallace) writes:
>Given that for evolution of life to start, a simple living organism must
>come together from amino acids etc. by accident; and that for any
>complex structure to fall together by accident is extremely improbable;
>then it looks pretty much like the odds against life appearing on any
>one planet could easily be more than 10^1000 to 1 against, and the
>number of planets in the visible universe is only about 10^22.

When you place hydrogen and oxygen together in a 2:1 ratio and provide
an energy source, what happens? Blooey! Every time? Yes, every time.
That's the way it is with life chemicals, there is nothing accidental
about their combination.  It's just basic organic chemistry at work.
We have very good evidence that the primordial chemical mixtures of
early planetary bodies contain the proper precursor compounds and
elements in abundance. We know that solar UV and electrical discharges,
lightning, will supply the necessary energy. We've done it in a test tube.
We haven't yet made the step to the enclosed cell, but with 10^23 precursor
molecules in every cubic meter, the combination is bound to occur.

Now none of that implies that Man must be the final result. Indeed the
odds may be 10^1000 against, though it has happened at least *once*.
But some form of evolving life is a certainty under those starting
conditions. Carbon chemistry is carbon chemistry everywhere and everywhen.

Gary

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

Date: 29 Jul 92 16:17:16 GMT
From: Gary Coffman <ke4zv!gary>
Subject: ETs and Radio
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (James Annis) writes:
>In article <[e-mail]> [e-mail] (Derek Wee) writes:
>>
>>Anyone have any good arguments FOR the existence of extraterrestrial
>>intelligence?
>>
>           11                 9
>sure:    with 10   stars in our galaxy, 10  galaxies in the observable
>    universe, the odds of us being unique start at
>      20
>    10  to 1 against.

Now subtract out all Population II stars, no heavy elements like iron,
and subtract out all multiple star systems, no stable planetary orbits,
and subtract out all blue giants and other short lived stars, now subtract
out all systems that don't have a planet in the liquid water zone, subtract
out all planets not at the correct stage of planetary evolution, ours is
billions of years old while conditions for life are a much smaller fraction
of that, now subtract out all the systems where life hasn't evolved from
primitive forms to advanced forms, life has existed on this planet for
a long time, humans much less so, etc.

That 10^20 starts shrinking mighty fast. Some "best guesses" by people
who've thought about the question say that there are perhaps 50 systems
in the galaxy that may have life as we know it.

Gary

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

Date: 29 Jul 92 20:23:12 GMT
From: Paul Dietz <[e-mail]>
Subject: ETs and Radio
Newsgroups: sci.space

I'm of the opinion that it has *not* been shown that the origin
of life is likely.

One problem with the arguments that "look, we can make X, Y and
Z in the lab, which have many of the features of life" is that
having many of the features of life is not enough.  Close doesn't
count here.  A good example is Fox's protenoids.  They look like
cells in that they are spherical and enclose a volume.  They have
multiple charged moieties that show generalized, nonspecific catalytic
function (just like any random protein will).  But are they "life"?
No, because they lack the crucial property of holding and expressing
genetic information.

One might call this unfounded optimism the "Coke Contest Fallacy".
The Coca Cola Company periodically holds contests where you have to collect
bottlecaps spelling a certain word or phrase.  As one starts to
play, hope abounds as more and more letters are found.  But at the end,
one letter never seems to show up, and the game period expires without
you winning.  That last letter, of course, is the one that controls
how many winners there were.

The analogy to origin of life is that certain common features, like
the fact that partially hydrophobic proteins form vesicles, will pop
out early.  This doesn't mean that life is much more likely, since a
rare, difficult and rate controlling event would be hard to discover
in the lab, by definition.

Some very basic problems remain in origin of life research.  One of
the most basic is:  "how do polymers formed by condensation (i.e.,
water removing) reactions form in an aqueous environment (where the
excess of water should drive the reaction the other way)."  As far
as I know, this has not been solved.  Life today solves this problem
with the use of complex enzymatic machinery and liberal expenditure
of ATP and other phosphorylated molecules.  Another is "how did
the bases of RNA form?"  The environment for the formation of adenine
and so on seems to be quite different from that forming amino acids
or the sugars that form the backbone of nucleic acids.  Yet another is
"how did the genetic machinery, for replication of the gene, and for
its expression, get started".  No convincing scheme has been presented,
although much imagination has been applied.

Perhaps we'll discover, some day, a simple path hardwired into chemistry
that leads to life.  Or, perhaps, if life really does require an accident,
the field will continue to produce hopeful but ultimately sterile suggestive
results.  I suspect the answer may not really be known until our
descendants explore many other stellar systems, or come into contact
with aliens who have.

If life really is somewhat rare, the place to look for ET signals is from
distant galaxies, broadcast by pan-galactic supercivilizations.  These
civilizations could be far enough away to evade the Fermi Paradox, since
ships in an intergalactic colonization wave would likely not travel straight
out from the starting point, but rather go to nearby galaxies, giving
a colonization wave speed significantly less than the speed of light.

    Paul F. Dietz
    [e-mail]



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

Date: Wed, 29 Jul 1992 20:30:00 GMT
From: russell wallace <[e-mail]>
Subject: ETs and Radio
Newsgroups: sci.space

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

>In article <[e-mail]> [e-mail] (russell wallace) writes:
>>Given that for evolution of life to start, a simple living organism must
>>come together from amino acids etc. by accident; and that for any
>>complex structure to fall together by accident is extremely improbable;
>>then it looks pretty much like the odds against life appearing on any
>>one planet could easily be more than 10^1000 to 1 against, and the
>>number of planets in the visible universe is only about 10^22.

>When you place hydrogen and oxygen together in a 2:1 ratio and provide
>an energy source, what happens? Blooey! Every time? Yes, every time.
>That's the way it is with life chemicals, there is nothing accidental
>about their combination.  It's just basic organic chemistry at work.
>We have very good evidence that the primordial chemical mixtures of
>early planetary bodies contain the proper precursor compounds and
>elements in abundance. We know that solar UV and electrical discharges,
>lightning, will supply the necessary energy. We've done it in a test tube.
>We haven't yet made the step to the enclosed cell, but with 10^23 precursor
>molecules in every cubic meter, the combination is bound to occur.

Yes, I realize that amino acids are bound to form under the appropriate
conditions. However, those amino acids are no more likely to
spontaneously assemble into a life form than 10^6 transistors placed in
a box and shuffled around are to assemble themselves into a working
computer.







--
"To summarize the summary of the summary: people are a problem"
Russell Wallace, Trinity College, Dublin
[e-mail]

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

Date: 29 Jul 92 20:33:55 GMT
From: russell wallace <[e-mail]>
Subject: ETs and Radio
Newsgroups: sci.space

In <[e-mail]> [e-mail] writes:
>The first part deals with an article in the May 1992 Scientific American, by
>John Horgan on page 30. The article discusses the work of Julius Rebek, Jr.,
>a chemist at MIT. Rebek has been developing molecules which self-replicate,
>much the same way that DNA does. He uses a simple system which duplicates
>some of the features of living systems. The system is so simple, that after
>a few steps, it ceases to demonstrate new qualities, but it points the way
>for developing evolutionary models based on non-living molecules, which
>could point the way to a better understanding of living systems.

>Here's how it works, in it's present version: three amines and an ester, all
>synthetic, are mixed in a chloroform solution. Each amine combines with an
>ester to produce an amide, each of the three different, which will self-
>replicate. That is, the amide will serve as a template for other amines and
>esters to cling to, and make another amide. Thermal jostling separates
>the two, and each goes on to produce more amides.

>The three slightly different amides replicate at roughly the same rate, but
>when irradiated with UV light, one amide mutates into a variant which
>reproduces much faster than the others.
>In another recent experiment, two esters and two amines were mixed to create
>four different amides. Two are duplicates of the earlier experiment, one is
>an even better replicant than the mutant, and one is sterile, that is, it
>cannot support replication at all.
>Unusually, each amide replicator can also serve as a template for the other
>amides, somewhat like the "hopeful monster" idea where new species would
>occasionally spring full-blown into being. However, due to the simplicity of
>the system, analogies to biological theory are still pretty weak.

As a matter of fact, they are nonexistent. What you have here is
*trivial* self-reproduction akin to the growth of salt crystals, not
non-trivial self-reproduction as required for life. This is because the
amide molecules do not store information about their own construction in
a blueprint which can be altered to create a different amide molecule,
and therefore they cannot serve as raw material for evolution. The
critical point is to get by random chance to a stage where evolution can
then take over, and the amide experiment does not do anything to fill
the gap.

>It has been mentioned already that a strict definition of life is still
>somewhat forthcoming, and that there is still a fuzzy border between the
>living and the nonliving.

No, there is not. A living entity is one which is capable of non-trivial
self-reproduction, and a non-living entity is one which is not. (Well,
there are fuzzy example, such as mules (which cannot reproduce
themselves, but which we regard as alive anyway), but these occur as the
products of systems which are fully alive. There is no fuzziness in the
boundary between a planet which supports life and one which does not.)

>Demonstrating that life-like structures can arise
>under primitive-earth conditions and that they can exhibit behavior similar
>to modern cells, to me, takes most of the wind out of the sails of those
>who contend that abiogenesis is improbable to the point of being impossible.
>We can demonstrate that structures can form which resemble fossil structures,
>we can demonstrate that these structures can perform many of the duties
>which modern cells need to perform, and we can demonstrate that many of the
>natural processes which produce these structures will produce similar
>structures under many conditions, meaning that although many types of processes
>may initiate life, those which go the farthest may all produce roughly the
>same product, leading towards a "molecular determinism" which standardized
>the form of the first life on earth, however many times it arose, and in
>however many places.

So what? However many globs of amino acids, lipids, RNA and whatever you
can produce in a test tube, you cannot produce a life form. Pointing to
globs of amino acids in a test tube and saying that this is close to
the spontaneous assembly of a life form is like pointing to a box of
10^6 transistors, jumbled up at random, and saying that this is very
close to the spontaneous assembly of a working computer. The point is
not the components, but their assembly into a working system.

>Proteinoid microspheres are near-proteins produced by polymerizing amino
>acids. A main contribution is from something called trifunctional amino acids
>which are found in such biologic-free samples as lunar rock, meteorites and
>bacteria-free terrestrial lava. The amino acids have informational and
>functional value. They order the formation of proteinoids and direct the
>structure and functions of the proteinoids themselves. The ordering, or non-
>randomness of the proteinoids is a function of the chemical structure of
>the amino acids, and does not require external ordering, direction through
>divine agencies, or extraterrestrial visitors. This has been demonstrated
>in the laboratory, and is the best argument against the "probabilistic"
>claims that life is a decendant of random processes.

[biochemical data deleted]

I'm not a biochemist, so I can't comment in detail on this information.
However, it would appear that nothing other than certain types of
chemical reactions have been demonstrated for proteinoid microspheres
(correct me if I'm wrong). This is irrelevant. The point is not that the
mere chemical components of living organisms are hard to form, but that
the system, composed of all the components arranged in the correct way,
is hard to form, because there are so many possible wrong ways for the
components to be arranged. (Similarly, because electricity and silicon
occur in nature does not imply that electronic computers do.)

>This implies that we are much closer to understanding the steps to cellular
>life than is commonly implied in popular accounts of abiogenic research, and
>demonstrates that the probabilistic models are missing a few assumptions. The
>main key here is that proteinoids should assemble themselves, and then
>conduct "molecular evolution" of structure and function, until at some point,
>they can be considered to be living cells.

Evolution before the existence of a life form is a contradiction in
terms. For Darwinian evolution to occur, there must be non-trivially
self-replicating entities, which store blueprints of themselves in an
information storage system, which can be mutated at random to create a
slightly different organism. A non-living entity does not have this, and
therefore by definition cannot undergo evolution (in the Darwinian sense
of a cumulative, directed series of changes).

--
"To summarize the summary of the summary: people are a problem"
Russell Wallace, Trinity College, Dublin
[e-mail]

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

Date: 29 Jul 92 20:51:37 GMT
From: Henry Spencer <[e-mail]>
Subject: ETs and Radio
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>Now subtract out all Population II stars, no heavy elements like iron,

Some of them might have enough for a small planetary system.

>and subtract out all multiple star systems, no stable planetary orbits,

I'm told this doesn't look like as big a problem as was once thought.

>subtract out all systems that don't have a planet in the liquid water zone,

This is where we get into real guesswork.  Note, though, that the liquid-
water zone is wider than we once thought -- Mars would have liquid water
if it was bigger.  (The idea that the "habitable zone" is very narrow and
Earth has just happened to stay in it has been discredited.)

>subtract out all planets not at the correct stage of planetary evolution,
>ours is
>billions of years old while conditions for life are a much smaller fraction

Really?  Please elaborate.  All you really need is liquid-water temperatures
and adequate materials.  The major changes in our planetary conditions over
the last few billion years have pretty well all been due to the presence of
life.  (The idea that Earth had a lucky escape from being another Venus has
also been discredited -- Earth's oceans would still be liquid even if it
had Venus's load of atmospheric CO2 today.)

>... now subtract out all the systems where life hasn't evolved from
>primitive forms to advanced forms, life has existed on this planet for
>a long time, humans much less so, etc.

But add in the potential for life to take faster routes than ours.  Some
of the dinosaurs might well have evolved intelligence if their history
hadn't been cut short a bit too early, and several other species on Earth
are not impossibly far from intelligence.  This is getting pretty far into
guesswork again, though.

>who've thought about the question say that there are perhaps 50 systems
>in the galaxy that may have life as we know it.

References, please.  There have certainly been *much* higher estimates too.

Also, why insist on it being life as we know it?


The only argument against extraterrestrial life/intelligence that strikes
*me* as being particularly telling is the Fermi Paradox:  if they're out
there, why didn't they colonize this planet long before we evolved?
--
There is nothing wrong with making      | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim|  [e-mail]  utzoo!henry

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

Date: 29 Jul 92 21:53:06 GMT
From: Henry Spencer <[e-mail]>
Subject: ETs and Radio
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (russell wallace) writes:
>However, one crystal is pretty much the same as another; none of them
>actually do anything (in the absence of humans to make use of them).

You've obviously never studied crystal properties.  They can be complex
and strange.  Incidentally, in some circumstances they can even display
a limited form of self-reproduction.

>... You actually need something like a cell to have
>self-reproduction at all, where by "self-reproduction", I mean
>non-trivial self-reproduction, not things like crystal growth...

Sorry, this simply isn't true.  Simple molecules in solution can reproduce
themselves, given favorable conditions.  RNA, in particular, does this.
Not well, and not quickly, by itself... but it does do it.

>for non-trivial self-reproduction to occur, the following must be present:
>An information storage unit which stores information on how to build the
>organism.
>Some machinery to construct a new organism.

With sufficiently favorable conditions or sufficient patience, the machinery
need be little more than a supply of suitable raw materials.  Don't confuse
a self-reproducing *system* with a self-reproducing *organism*; just because
you can't draw a line around it and say "this is where it ends and the rest
of the world begins" doesn't mean it's not a real system, capable of
both reproduction and evolution.

>In organic life forms, DNA is the blueprint, which is interpreted by the
>transcription process, and copied by splitting the strands and adding
>matching nucleotides to each. The enzymes are the machinery, and there
>is a cell membrane around the whole thing (which is needed, otherwise
>the enzymes will float away and be lost).

If circumstances are favorable, you don't need the cell membrane.  There
is no fundamental problem with just having the blueprint and the machinery
floating free in solution, if it's concentrated enough (the proverbial
"small warm pond").  The cell membrane does confer a very important
advantage -- the benefits of better machinery are available only to the
blueprint that produced them, not to all blueprints at large -- but it
is not essential to the first stages.

Both DNA and RNA are used as blueprints in organic life, actually, and
RNA almost certainly came first.  DNA is better, but it needs elaborate
support machinery.  RNA can perform enzymatic functions all by itself.
The latest relevant research result is that the ribosome -- the center
point of the transcription process -- appears to be primarily RNA with
some proteins to assist, not vice versa as once thought.  The first
identifiable life was almost certainly mostly or entirely RNA.
--
There is nothing wrong with making      | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim|  [e-mail]  utzoo!henry

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

Date: 29 Jul 92 19:23:04 GMT
From: Brent Kellmer <[e-mail]>
Subject: Glaciation on Mars
Newsgroups: sci.space

Perhaps someone out there could help me with a problems:

I'm trying to find out if there is any evidence for past glaciation on
Mars.  Any input?

Thanks.

Brent Kellmer
[e-mail]

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

Date: Wed, 29 Jul 1992 18:43:28 GMT
From: Bill Seward <[e-mail]>
Subject: Happy Birthday!
Newsgroups: sci.space

According to my "Wonders of the Universe" calandar, on this day in 1958,
NASA was founded.

Happy Birthday NASA!

-------------------------------------------------------------------------------
| Bill Seward               |                                                 |
| [e-mail] | Pithy saying wanted.  Inquire within.           |
| [e-mail]     |                                                 |
-------------------------------------------------------------------------------

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

Date: 29 Jul 92 19:15:29 GMT
From: Matthew DeLuca <[e-mail]>
Subject: Soyuz as ACRV
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>In article <[e-mail]>, [e-mail] (Matthew DeLuca) writes:

>>I really will be surprised, though, if we end up using Soyuz.  It's a neat
>>idea on paper, but I think the number of technical problems that need to be
>>overcome will outweigh any savings from using already-existing hardware.
>
>Huh? What already existing hardware for assured crew return? Since NASA is

The 'already existing hardware' is the Soyuz; I was trying to say that the
cost savings from using a currently-existing vehicle (Soyuz) will likely
be eaten up by the cost of converting and certifying it for duty, so we
won't really be saving that much.

>Plus I can see cases where they want to send up one or two specialists without
>blowing a full shuttle flight.

If they can launch people to a 28.5 degree orbit from Russia, that would be a
good use.  I can see us sending a couple of people over to Russia for a
quick trip up.  We'd need a docking adapter, but no big deal.
--
Matthew DeLuca                      "I'd hire the Dorsai, if I knew their
Georgia Institute of Technology      P.O. box."
Office of Information Technology                - Zebediah Carter,
Internet: [e-mail]              _The Number of the Beast_

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

Date: 29 Jul 92 18:14:00 GMT
From: [e-mail]
Subject: Space Station Freedom assembly questions
Newsgroups: sci.space

Source-Info:  Sender is really [e-mail]
Source-Info:  Sender is really [e-mail]

In article <[e-mail]>, [e-mail] (Gerald Cecil) writes...
>(Reformatted to be more readable, sorry.)
>I'm trying to formulate a letter on the Space Station to my Congresspeople.
>I have several questions on Space Station assembly issues that I'd
>appreciate some input on.  Thanks in advance!

Not a correct number. JR Tompson in congressional testimony stated that there
is a very good chance of losing an orbiter during the space station assembly
process (for full outfitting and ten years of flights) This is about one in 50
probability or one in 70 for the current schedule. We have had 24 flights
since Challenger, the same amount as before Challenger and it *seems* that
the program is far more on schedule and many of the criticality one problems
have been fixed since Challenger (APU's have been targeted as the most
dangerous problem to shuttle safety and have been extensively redesigned)

>1. What is the current thinking on Shuttle accident probabilities and the
>impact on Space Station assembly?  I recall reading of an Air Force
>assessment Post-Challenger that compounded to near certainty of a
>disabling accident in 20 flights.  (Not necessarily an explosion, but at
>least removal of an Orbiter from the fleet.) If this is generally accepted,
>but not discussed, maybe it needs some airing here(!)
>


>2. What is the status of Shuttle-C?  Is it supposed to play any role in
>Station assembly or for logistical support (= hauling water & hydrazine)?

Shuttle C is dead. The mockup here at Marshall has been dissassembled and
no further studies have been planned.  All of our current heavy lift eggs are
going with NLS.

>
>3. The only NON-POLITICAL argument that I have heard as to why Space
>Station components should NOT be launched on Energia is the comparatively
>northern latitude of the launch site and consequent payload loss for
>cross-plane maneuvers.  The penalty in my estimation doesn't look that bad,
>given the large intrinsic capability of Energia, so are there
>obvious bona-fide TECHNICAL problems (e.g. no engine restart capability)
>that someone might care to comment on?
>

The cross plane maneouver from 51 degrees down to 28.5 degrees has an
enormous penalty in payload.  This is why you will NEVER see a Soyuz at
SSF orbit unless it is on Energia.  The payload penalty will drop Energia's
delivered payload to around 50,000 pounds.  I do not know the dynamics and
this estimate is based on what I have read in generalities regarding that
Energia could at best only deliver a Soyuz to SS Freedom. Anybody have
Delta V numbers for such a plane change?

>4. Does the present baseline Station have any real prospects for expansion?
>I'm thinking of intrinsic power or dynamic (structural) compromises that
>would prohibit additional modules.

There is essentially no limit to the possibilites for expansion with the
open truss architecture of SS Freedom.  This was one of the FUNDAMENTAL
design drivers for this architecture.  It may not have all of the
capabilities that we want now, but it can expand to accomodate much more
power, internal Hab area and so forth.

Note the problems that they are having with stabilization and reboost
currently with MIR.  The spam in a can approach to Space stations and
the adding of modules such as has been the case with MIR has led to severe
problems in control requiring the flight we read of right now to continue
to fix the stabilization system and add new propulsion.

For more information ask Bill Higgins here for a copy of Gordon Woodcock's
paper on SS Freedom presented at the 1989 ISDC conference that aged Bill
at least a year or two.  Hope you still have some of that stuff Bill.

Dennis, Wingo University of Alabama in Huntville

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Revive the Saturn V!
------------------------------------------------------------------------------
Saturn Configuration        #F1A engines    #STME engines Payload to LEO

S1C-1                 1        1        50,000 lbs
S1C-2 Common tankage w/S1C-1    2        1 or 2        110,000 lbs

Common tankage for next phase

S1C-3                3        2        180,000 lbs
S1C-4                4        2 or 3        235,000 lbs
S1C-5 Full Saturn V config    5        5 plus 1 s/3    305,000 lbs
----------------------------------------------------------------------------

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End of Space Digest Volume 15 : Issue 051
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