Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_0/V15NO053.TXT

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

Date: Fri, 31 Jul 92 05:00:07
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #053
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri, 31 Jul 92       Volume 15 : Issue 053

Today's Topics:
              Answers to PLANES of the ecliptic question
                Antimatter (was propulsion questions)
               Biogenesis (was: ETs and Radio) (2 msgs)
                        Clinton Space Position
                         ET's, life in space
                            ET's and Radio
                            ETs and Radio
                       Geotail launch (2 msgs)
                                Months
       Russian/French Soyuz TM-15 docks with Mir space station
                            shuttle --ufo?
          Space Station Freedom assembly questions (2 msgs)
                       trivial self-replication
                WANTED: Info on Pegasus Launch System

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
    "Subscribe Space <your name>" to one of these addresses: listserv@uga
    (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle
    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: Thu, 30 Jul 92 12:58:23 BST
From: [e-mail]
Subject: Answers to PLANES of the ecliptic question

> What would we measure this precession against, in order to
distinguish it
> from the revolution about the galactic center, and oscillation
about the

> galactic plane?
>


My gut feel is that no two circuits will be the same. Since a
revolution is on the order of 100MY or so, there will be changes in
stellar populations, changes in distribution due to mass falling into
the center, different galactic "MASSCONS" at different points in the
orbit that change over time. Even if the interior rotates "sort of
solid body" the sort of is not really solid body. There is
differential rotation as you go inwards. Just not as much as there
"should" be.

I suspect Sol's orbit is rather chaotic.

And then, with the last orbit or so Milky Way has had a near approach
of a small galaxy and the opposite rim from us is bent upwards. There
is a trail of gas behind one of the Magellanic clouds (there is
apparently a third one behind one of the ones we can see). Thus we
are in a "peculiar" galaxy and our orbit may well have been perturbed
to some extent by that pass.


Additionally, current thinking is that galactic near misses are quite
common. On a scale of 100MY per orbit, we might have seen a
significant perturbation every few orbits. Keep in mind that the 2.2M
LY between hear and Andromeda could be closed and reopened in the
time span of just a couple orbits.

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

Date: 30 Jul 92 04:56:42 GMT
From: Kenneth Ng <sugra!ken>
Subject: Antimatter (was propulsion questions)
Newsgroups: sci.space

In article <[e-mail]:, [e-mail] writes:
: In article <[e-mail]>, [e-mail] (Henry Spencer) writes:
: |> Antimatter isn't a very efficient explosive.  If you dropped an anti-iron
: |> cannonball, it would just sit there and sizzle.  (The radiation would make
: |> the immediate neighborhood very unhealthy, mind you.)
: No.  Dropping an anti-iron cannonball -- or, indeed, exposing it to air
: -- would vaporize it in short order.  The antiiron vapor would then quickly
: mix with very hot air, and most of the antimatter would annihilate in
: short order.

What would happen in a weightless environment?  Would it kind of do something
like what the candle in the shuttle did?

--
Kenneth Ng
Please reply to [e-mail] for now.
Apple and AT&T lawsuits: Just say NO!

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

Date: Thu, 30 Jul 1992 08:10:49 GMT
From: russell wallace <[e-mail]>
Subject: Biogenesis (was: ETs and Radio)
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Steven J. Edwards) writes:

>In article <[e-mail]> [e-mail] (russell wallace) writes:
># In <[e-mail]> [e-mail] (Gary Coffman) writes:
>#
>#> 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.

>The current leading theory is that ribonucleic acids were the first
>step ont he biogenesis chain.  A recent (early 1992.07) issue of
>_Science_ had a very convincing article about self assembly of
>replicating clusters of pure and nearly pure RNA molecules.  It turns
>out that a regular ribosome (protein assembler) is still remarkably
>functional even when almost all of its structural amino acids are
>removed.  Before this research, many scientists had a deep suspicion
>that nucleic acids, either DNA or RNA, got the ball started; now we
>have experimental evidence.

>Therefore, there is now no need to appeal to deep time and large
>reaction volumes for complex protein self assemblers and self
>replicators: the RNA molecules got there first.

>A suggested scenario:

>1) Significant quantities of single or small chain amino acids form
>spontaneously, but no "wonder molecule" replicator is seen.

>2) Ancestral variants of rRNA molecules form clusters spontaneously;
>these have partial replicative ability in varying degrees.  Cluster
>replication is irregular and probably not too accurate as far as
>faithful duplication of the parent template.

>3) Some rRNA clusters are capable of incorporating naturally formed
>amino acid chains.  Some of these cases the amino acids enhance
>replicative fidelity and productivity; natural selective pressure
>begins due to limited supplies of spontaneously formed amino acids.

>4) At some point an rRNA replicating cluster using amino acids becomes
>capable of partial synthesis of useful amino acids.  This replicator
>gains a tremendous advantage over imperfect and less efficient
>replicators who must compete for the limited spontaneous amino acid
>production.

Why would it gain an advantage, given that without a cell membrane, the
amino acids it synthesizes would float away to benefit the other
clusters just as much as the synthesizer?

As a matter of interest, just how could an RNA cluster synthesize amino
acids? From what raw materials? I thought synthesizing amino acids
required energy, and therefore a complex set of enzymes to extract that
energy from something.

>5) The protein making rRNA clusters become self sufficient and the
>first true ribosomes are the result.  This is a good candidate for
>"first life".

Yes, it certainly would be, except the problems again arise:

without a cell membrane, how would the "first life" cluster gain an
advantage, when all its carefully synthesized enzymes floated away to
benefit other replicators?

you *still* need the full machinery for non-trivial self-reproduction.
This means that the RNA must serve as a blueprint carrying the
information to synthesize the proteins which assist with the synthesis
of proteins and the replication of the RNA. What is the simplest system
capable of doing all this, and is it simple enough to have a reasonable
probability of falling together by chance? I don't think so. Why would
you not require the full transcription apparatus?

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

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

Date: 30 Jul 92 11:58:00
From: "Steven J. Edwards" <[e-mail]>
Subject: Biogenesis (was: ETs and Radio)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (russell wallace) writes:
#> In article <[e-mail]> [e-mail] (russell wallace) writes:
#>#  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.
#
#> The current leading theory is that ribonucleic acids were the first
#> step ont he biogenesis chain.  A recent (early 1992.07) issue of
#> _Science_ had a very convincing article about self assembly of
#> replicating clusters of pure and nearly pure RNA molecules.  It turns
#> out that a regular ribosome (protein assembler) is still remarkably
#> functional even when almost all of its structural amino acids are
#> removed.  Before this research, many scientists had a deep suspicion
#> that nucleic acids, either DNA or RNA, got the ball started; now we
#> have experimental evidence.
#
#> Therefore, there is now no need to appeal to deep time and large
#> reaction volumes for complex protein self assemblers and self
#> replicators: the RNA molecules got there first.
#
#> A suggested scenario:
#
#> 1) Significant quantities of single or small chain amino acids form
#> spontaneously, but no "wonder molecule" replicator is seen.
#
#> 2) Ancestral variants of rRNA molecules form clusters spontaneously;
#> these have partial replicative ability in varying degrees.  Cluster
#> replication is irregular and probably not too accurate as far as
#> faithful duplication of the parent template.
#
#> 3) Some rRNA clusters are capable of incorporating naturally formed
#> amino acid chains.  Some of these cases the amino acids enhance
#> replicative fidelity and productivity; natural selective pressure
#> begins due to limited supplies of spontaneously formed amino acids.
#
#> 4) At some point an rRNA replicating cluster using amino acids becomes
#> capable of partial synthesis of useful amino acids.  This replicator
#> gains a tremendous advantage over imperfect and less efficient
#> replicators who must compete for the limited spontaneous amino acid
#> production.
#
# Why would it gain an advantage, given that without a cell membrane, the
# amino acids it synthesizes would float away to benefit the other
# clusters just as much as the synthesizer?

This is trivally answered: first, the synthesized products do not
merely float away because they have assorted polar regions that can
interact with the synthesizer, and second, other similar or identical
replicators nearby would share in the benefit of peptide production
from other than themselves.

# As a matter of interest, just how could an RNA cluster synthesize amino
# acids? From what raw materials? I thought synthesizing amino acids
# required energy, and therefore a complex set of enzymes to extract that
# energy from something.

All chemical reactions require energy to start; this is called the
"activation energy" of a reaction.  There are several natural sources,
some of these are: photons from the Sun, ambient kinetic energy
(heat), stored chemical energy from previously producted compounds,
and lightning.

#> 5) The protein making rRNA clusters become self sufficient and the
#> first true ribosomes are the result.  This is a good candidate for
#> "first life".
#
# Yes, it certainly would be, except the problems again arise:
#
# without a cell membrane, how would the "first life" cluster gain an
# advantage, when all its carefully synthesized enzymes floated away to
# benefit other replicators?

Again, the peptides do not just "float away"; peptides that did get
loose would benefit similar (or identical) replicators.  These
secondary replicators would likely be physically close anyway.

# you *still* need the full machinery for non-trivial self-reproduction.

No.  Simple RNA replicator molecules can do it with only naturally
occuring amino acid molecules.  Complex RNA replicators may synthesize
some to all of the needed amino acids (and other molecules).

# This means that the RNA must serve as a blueprint carrying the
# information to synthesize the proteins which assist with the synthesis
# of proteins and the replication of the RNA. What is the simplest system
# capable of doing all this, and is it simple enough to have a reasonable
# probability of falling together by chance? I don't think so. Why would
# you not require the full transcription apparatus?

Information necessary for early replication does not need the "full
transcription apparatus" because it is not based on any genetic code.
Early RNA replicators had their replication information stored in
their three dimensional structure, not in any one dimensional coded
strand.  RNA chains act as sort of a "poor man's emzymes": there are
only four bases instead of dozens of amino acids, but there still is a
lot that can be accomplished.  Laboratory results show that: both RNA
and amino acids form under natural conditions, complex RNA structures
form spontaneously, some these structures have the power of
replication and peptide synthesis.  Of course, none of the early
replicators had the efficiency and fidelity of today's genetic
apparatus.  But they didn't need it either.

No cell like membranes are needed.  No DNA is needed.  No tricky DNA
synthesis and transcription enzymes are needed.  No genetic code is
needed.  None of these are needed for "first life".  All of these can
be evolved from the early replicators.

There is no need for a special miracle for Earth, therefore it is
unlikely that Earth is the only life bearing planet.  If there is a
miracle, then it is the creation of a universe with physical laws that
permit (actually, strongly encourage) development of replicators and
intelligence.

This thread should probably be continued in the talk.origins
newsgroup.

 [The above opinions expressed are my own; not necessarily held by others.]
      == Steven J. Edwards           Bull HN Information Systems Inc. ==
      == [phone]              300 Concord Road         MS 820A ==
      == [e-mail]     Billerica, MA 01821          USA ==
"That Government which Governs the Least, Governs Best." -- Thomas Jefferson

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

Date: Thu, 30 Jul 92 11:40:32 BST
From: [e-mail]
Subject: Clinton Space Position

> because it's being done, but there's a point of view that there's
some
> benefit to not being extensively involved in the politics of other
countries.
>

I will agree with John that mucking about in other nations politics
with guns is probably not on.

But the very media in which we are now communicating is the death
knell of the nation state, or at least as we have known it. We are
ONLY at the beginning of this, which may be hard for some of us to
recognize since we have been involved with network chats for 10-20
years (When I first connected to ARPANET there were about 20 sites on
it)

Yes, Japanese advertisers may pull out advertising in something about
Pearl Harbor because they don't like to be reminded that they started
a holocaust and ended up reaping it themselves: the first time in
their history that the "Divine Wind" was on someone else's side. You
had better believe that was a hard knock. They not only lost the war,
but they had their religion turned against them. Well, one of these
days our Japanese compatriots will start taking more of a part in
this forum and others and will have their chance to be taken to task
... and to tell US directly what they think is wrong in the US and
Europe and elsewhere.

That will make us all richer in understanding. There is no better way
to have your pet ideas undermined than to get a viewpoint from
someone outside the rhetoric of your society point them out.

I would go furthur and say that there are probably quite a few
Japanese students and faculty that "listen in" to this forum but who
are afraid, for cultural reasons, of taking part in the network rough
and tumble. Well, I personally invite you to come in and express your
ideas ... and take critique of everything you know and believe in,
just like the rest of us do.

We are the vanguard that is taking the eraser to the silly little
lines on the world maps. You know, the ones that you can't see from
the moon... And we need a thousand Henry's (Hmmm, a KiloHenry?) to
help speed up the process.

                    Live Free or Die
                    Dale Amon

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

Date: 30 Jul 92 08:20:02 GMT
From: russell wallace <[e-mail]>
Subject: ET's, life in space
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Tom) 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

>Not accident.  Think in statistics.  Given umpteen billion gallons
>of warm, super gunky sea, what are the possibilities that any one
>group of amino acids could form self-replicating protiens...

I *am* thinking in statistics. If the smallest possible self-replicator
is 1000 amino acids in size, and there is only one self-replicator of
that size, and supposing there are 20 possible amino acids, then the
odds against any 1000-amino acid chain being a self-replicator are
20^1000 to 1. Against this statistic, the total number of molecules that
can have been formed in the visible universe since the beginning of
time is insignificant.

(Note: I know RNA is probably more significant than protein in forming
the first life form, this is just an example: the argument holds with
slightly greater force regarding RNA, since nucleic acids are rarer than
amino acids (harder to form in the test tube). Also, I am using
"self-replicator" to mean *non-trivial* self reproduction.)

>They wouldn't even have to self-replicate, just affect each other.
>If one set of reactions happened to get into some kind of positive
>feedback....

Why would they not have to self-replicate? If positive feedback was
sufficient, then a hydrogen flame should be the first life form. (And
remember, we not only need self-replication, we need non-trivial
self-replication.)

>Check out 'protien spheres' in some biology book, BTW.  It's not
>that unusual for non-life to mimic life.

So what? We need actual life, not something that just mimics it. And
mimic is exactly all that those protein spheres do, given that they
don't have any equivalent of genetic information.

>Also, remember that
>protiens are building blocks, information, and catalysts in the
>cell.  And yet the basis for protiens (amino acids) are really
>easy to form, as the Miller experiment back in the 50's showed.

Yes, I've been *assuming* that huge quantities of amino acids are
present, and showing that even so, assembling those amino acids into a
life form is no mean task. (BTW: nucleic acids, which are at least as
important as amino acids, are a lot harder to form.)

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

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

Date: Thu, 30 Jul 92 12:40:22 BST
From: [e-mail]
Subject: ET's and Radio

> If life really is somewhat rare, the place to look for ET signals
is from
> distant galaxies, broadcast by pan-galactic supercivilizations.
These
>


Although we'd better look for the odd laser that happens to be
pointing at us. Or maybe look for a source of modulated neutrinos. Or
maybe start opening worm holes in the Plank-scale froth to see what
the latest news is. The chances that advanced civilizations are
spewing vast amounts of energy into the void in order to transfer a
few Giga bits bits from point A to bit strains credulity to the
breaking point.

Massive radio broadcast of information with high power transmitters
is a transient phase of civilizations. In our own case it probably
will have a total time span of 150 years or less.

Now I left out some other uses of broadcast, ie NavAids and the like
may be useful on a planetary surface. But the power of those if going
to be just sufficient to do the job. And in a technology thousands of
years advanced beyond our own, that is liable to be damned little
ERP.

So I think the chances of seeing intelligent radio signals in a
distant galaxy is related to the number of civilizations AT OUR STAGE
that existed there n years ago, where n is also the number of light
years distance.

It also makes the current SETI search on megachannels not a search
for intelligent life per se, but a search for intelligence that is
within +/- 75 years of our own technology.

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

Date: Thu, 30 Jul 92 12:27:44 BST
From: [e-mail]
Subject: ETs and Radio

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


Not necessarily true. It depends a lot on the distances. Ie, a
stellar pair separated by Jupiter-distances or more could have
closely bound stable terrestrial planetary orbits.

The question might be whether the planets could form in that case.
The argument is that Jupiter is responsible for there not being a
planet where the asteroid belt is today, and for Mars being a bit on
the smallish side. An M0 star at that position might well have
precluded formation of an Earth sized planet (with tectonics to keep
the carbon tucked away) within the life zone of a G star.

But if you put it at a Saturnian or Neptunian distance?

Also, if you had two very close bound stars, you could have stable
orbits about the pair. Once again, the sizes and such are important
because you might preclude terrestrial planets in the combined life
zone.

So it is really hard to make conclusions about multiple star systems
since we don't know AT ALL whether planetary systems will form in
them, but we do know that IF formed, they can exist in many types of
binary systems.

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

Date: 30 Jul 92 08:19:46 GMT
From: Tero Siili <[e-mail]>
Subject: Geotail launch
Newsgroups: sci.space

Question: was last Friday's Geotail launch (on Delta, I think) succesful?  I found nothing in sci.space.news on the topic, although no news is often good news...

Respond preferably by e-mail to [e-mail]

Best regards,

Tero Siili
Finnish Meteorological Institute

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

Date: Thu, 30 Jul 1992 12:50:00 GMT
From: "E. V. Bell, II - NSSDC/HSTX/GSFC/NASA - (301" <[e-mail]>
Subject: Geotail launch
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Tero Siili) writes...
>
>Question: was last Friday's Geotail launch (on Delta, I think) succesful?  I found nothing in sci.space.news on the topic, although no news is often good news...
>
>Respond preferably by e-mail to [e-mail]
>
>Best regards,
>
>Tero Siili
>Finnish Meteorological Institute

    I watched the launch on NASA Select at Goddard and the launch
    was picture perfect! Not a hitch. Now as far as to whether or
    not the spacecraft is operating as planned, I haven't heard
    since. By the way, the launch time was 10:26 EDT (14:26 UTC)
    on 24-July-1992 for those who may care and don't know.

+------------------------------------------------------------------------------+
|  Dr. Edwin V. Bell, II    |  E-mail:                       |
|  Mail Code 633.9        |    (SPAN) NCF::Bell               |
|  National Space Science    |    or   NSSDC::Bell               |
|    Data Center        |    or  NSSDCA::Bell               |
|  NASA                |    or  NSSDCB::Bell               |
|  Goddard Space Flight Center    |   (Internet) [e-mail]       |
|  Greenbelt, MD   20771    |                           |
|  [phone]        |                           |
+------------------------------------------------------------------------------+

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

Date: Thu, 30 Jul 92 16:18:11 EDT
From: Tom <[e-mail]>
Subject: Months

>But don't forget that the Romans "moved" the first of the year from March to
>January for religious/family reasons which had nothing whatsoever to do with
>precession, variations in earth's orbit or rotation, or any other
>astronomical justification.  Remember, OCTober was formerly the 8th month and
>DECember was the 10th.

I thought the reason was because the Romans added two months:  August, after
Augustus ceaser, and July, after Julius Ceaser?  Since they were both before
SEPTember, OCTober, etc, the cute numbering system broke down...

-Tommy Mac                     .  "  Malcolm X:      +
.------------------------  +                      *       +
|   Tom McWilliams; scrub       ,     .  You've seen the hat,  "        +
|  astronomy undergrad, at     *       +;.     .  '
| Michigan State University   '                      .    "
|   [e-mail]                        '      ,  *
|       [phone]       ;  +  '  now catch the movie!           *
'-----------------------

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

Date: Wed, 29 Jul 1992 19:54:15 GMT
From: Glenn Chapman <[e-mail]>
Subject: Russian/French Soyuz TM-15 docks with Mir space station
Newsgroups: sci.space

     The Russian/French Soyuz TM-15 mission successfully docked with the CIS
(Commonwealth of Independent States) Mir space station today (July 29).
Docking time was not stated after the fact but was expected at 11:05 am
Moscow time (1:05 am PDT).  Lunched on July 27th the Soyuz crew transferred to
the station were cosmonauts Anatoli Solovyov, Sergei Avdeyev from CIS, plus
French "spationaut" Michel Tognini.  The mission is now stated as lasting 12
days on board the station.  Greeting them were Alexander Viktorenko and
Alexander Kaleri, who spent 134 days in orbit.  The Radio Moscow report
stated that contracts for an additional 4 French missions during the
next decade were currently proceeding.
     One interesting opportunity is open for people who have access on their
cable to a TV channel from France, as we do here in Vancouver.  French TV
naturally gives this mission much more coverage than the regular news.
Indeed last night there was an lively presentation about the cosmonaut
spacesuits in a "Johnny Carson" like show.  Keep an eye on that channel if
you can get it.
                                                        Glenn Chapman
                                                        School Eng. Science
                                                        Simon Fraser U.
                                                        Burnaby, B.C., Canada
                                                        [e-mail]

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

Date: 30 Jul 92 15:53:12 GMT
From: "Bill Jamerson SPS Pres." <SPS@helios>
Subject: shuttle --ufo?
Newsgroups: sci.space,sci.space.shuttle

a friend of mine reports having seen on WCMH evening news from Columbus,oh,
a report about the space shuttle seeing something like unto a UFO while up
earlier this year. He thinks it was either the last Columbia mission or
the Endeavor mission (more likely).
 The footage shown (taken from orbit by the shuttle) was a shiny object
apparently in orbit below the shuttle, which suddenly darted in a different
direction. immediately following, the footage showed a flash of light
originating form below where the object had been.  THere was some speculation
that it may have been a UFO.
  Did anyone else see or hear about this? if so, what else do you know?
  If someone from NASA could give us any info, that would be greatly
appreciated.
  THank you.

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

Date: Thu, 30 Jul 92 12:15:25 BST
From: [e-mail]
Subject: Space Station Freedom assembly questions

> still somewhat suspect.  On one launch, the second stage failed.
Not
> good. There have been only a couple launches, so there is little
basis
> to predict reliability.  There could be problems with things like
>


On the FIRST launch. Not all that unusual to have problems with a
first flight.

True, it has not had much flight history. Neither has Pegasus.
Neither has SSTO. By that logic we will still be flying Delta's and
the shuttle a century from now.

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

Date: 30 Jul 92 13:56:49 GMT
From: Edmund Hack <arabia!hack>
Subject: Space Station Freedom assembly questions
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
(The >> below is from a response I wrote on what technical problems
there might be in launching Freedom on Energias)
>> still somewhat suspect.  On one launch, the second stage failed.
>Not
>> good. There have been only a couple launches, so there is little
>basis
>> to predict reliability.  There could be problems with things like
>>
>
>
>On the FIRST launch. Not all that unusual to have problems with a
>first flight.
>
True, but when the number of flights is 2 (or is it 3?), one of which
(Buran) didn't have the upper stage (according to my fuzzy
recollection), that could be significant.  Also, there would need to be
much fuller disclosure of what went wrong so a rational decision could
be made.

>True, it has not had much flight history. Neither has Pegasus.
>Neither has SSTO. By that logic we will still be flying Delta's and
>the shuttle a century from now.

There is a big difference in risking a few lightsats (on the Pegasus
launches) and a multiBillion $$ program.  Note that out of two launches
of Pegasus, the second was a partial failure due to an upper stage
separation problem. (Note: this is not a slam at OSC - I admire what
they have done and as an engineer, I know that Things Happen.)  The
third Pegasus launch has been delayed again due to a ground test failure
of the new upper stage separation mechanism.

As for SSTO, it has 0 launches.  I also wish the Delta Clipper folks the
best, as what they are doing could be the Next Big Thing in aerospace.

--
| Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
| [e-mail]    SpokesPersonp(Me,or(NASA,LESC)) = NIL
|   **** Papoon for President! You Know He's Not Insane!! ****

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

Date: Thu, 30 Jul 92 16:22:28 EDT
From: Tom <[e-mail]>
Subject: trivial self-replication

>>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.

>Again, if it is replicating by itself, it is performing *trivial*
>self-reproduction, because it is not carrying any genetic information.

So what if it isn't carrying genetic information?  Self-replication is
self-replication.  Evolution will favor more complex forms, and eventually
it won't be 'trivial' anymore.  BTW, what is the definition of 'trivial'
in this context?  And no, evolution does not require DNA.  In this context
(usually called chemical evolution) it is just the process by which those
structures that replicate (whether 'trivially' or not) come to dominate.

>If the only machinery required is the stuff floating around all over the
>place (free amino acids etc.) then you have trivial self-reproduction
>which does not count, because even if RNA can replicate in this context,
>it is trivial self-reproduction because the RNA does not have or need
>any genetic information.

By what standards are you deciding that it 'doesn't count'?  If it can be
demonstrated (as I think it has, both in my own studies and in the
synopses offered here of late) that life processes can arise on their
own, without the infamous hidden watchmaker, or without the improbable
'protien of the Ninth Configuration', then what exactly, does 'not
counting' mean?  That we aren't here?  Ps- it's been mentioned already,
but RNA doesn't need genetic material, because it IS genetic material.
If we could talk to a piece of DNA, it might say that we existed for IT.

Aaaaand, as long as you have such a great handle on the defintion of life...

1)  Are viruses alive?  They reproduce non-trivially (by what I can get
    of your defintion from context)

2)  If humans built self-sufficient space colonies, would it mean that
     Gaia (the entire biosphere) had reproduced?  Evolved?

3)  Is human culture, as a whole, an organism?  It feeds, makes wastes,
    evolves, etc...

-Tommy Mac                     .  "  Malcolm X:      +
.------------------------  +                      *       +
|   Tom McWilliams; scrub       ,     .  You've seen the hat,  "        +
|  astronomy undergrad, at     *       +;.     .  '
| Michigan State University   '                      .    "
|   [e-mail]                        '      ,  *
|       [phone]       ;  +  '  now catch the movie!           *
'-----------------------

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

Date: 30 Jul 92 14:47:41 GMT
From: [e-mail]
Subject: WANTED: Info on Pegasus Launch System
Newsgroups: sci.space

A talk I attended yesterday briefly mentioned the Pegasus Launch System.
First tested in 1990, it was described as a solid fuel rocket launched
from a B-52 which could carry 100 - 200 kg into orbit.  Could anyone please
point me to more information on this system.

Thanks in advance.

Keith S Cover

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

End of Space Digest Volume 15 : Issue 053
------------------------------