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Subject: SPACE Digest V10 #103

SPACE Digest                                     Volume 10 : Issue 103

Today's Topics:
               More linguistic tidbits
     Re: Galileo Jovian atmospheric probe -- is it sterilized???
           Re: space news from Aug 14 AW&ST
          Re: Risk of NOT launching Galileo
      Re: Time Urgent: Voyager movies Oct 2 on satellite or tape
             Re: Mars Mission ship design
          Re: Risk of NOT launching Galileo
        Re: NIMF proposal from Martin Marietta
         YAHSS (Yet Another Henry Spencer Signature)
      Re: Plutonium in space (was Risk of NOT launching Galileo)
      Re: Alternative Space Goals, Anyone? (was Re: SpaceCause)
----------------------------------------------------------------------

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Date:       Wed, 27 Sep 89 11:39:25 EST
From: [e-mail]
Subject:    More linguistic tidbits

   So far I have seen Venerean,  Venereal and even Cytherean, but what ever
happened to Venusian?

John Coughlin    Net: [e-mail]   Vox: 613-541-6439   Fax: [phone]

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

Date: Wed, 27 Sep 89 14:47:07 PDT
From: Peter Scott <[e-mail]>
Subject: Re: Galileo Jovian atmospheric probe -- is it sterilized???

cs.utexas.edu!mailrus!jarvis.csri.toronto.edu!csri.toronto.edu![e-mail]  (Wayne Hayes) writes:

> So if there's "bugs" on Jupiter,
>they're certainly deserving at least as much evolutionary "respect" as
>anything on Earth, probably having evolved to a large degree as much as we
>have.
>[...]
>    I guess it is a somewhat subjective opinion (though one that
>many people take *very* seriously, both with reason and strong emotion --
>just ask any "Trekkie" who believes in Gene Roddenberry's "Prime
>Directive"), but I just strongly believe that we have no right to go
>screwing around with an environment we know nothing about.

Well, you don't get anywhere without taking risks, or the fish would never
have crawled out of the ocean (credit: Hitch Hiker's Guide to the Galaxy).
It all depends on whether the risk is worth the payoff.  If we never trod on
a new piece of ground because we were afraid of what we *might* squash, pretty
soon we'd be shut up in our bedrooms, breathing quietly for fear that our next
inhalation might capture the only remaining survivor of an incredible strain of
bacteria which would be slain by our white corpuscles.  Of course, taking this
point of view to the other extreme leads to actions like the firing of the
Amazonian rain forest, and to hell with their endangered species, so prudence
is needed.

However there is ample evidence that the A.R.F. contains unique and potentially
valuable organisms which are destroyed by firing.  The same cannot be said for
Jupiter's atmosphere.  What's needed is an exploratory probe to determine the
composition of the latter and find out what *is* there... which appears to be
what we are doing.  If the Jovian microbes are so fragile that they would be
destroyed by whatever terrestrial microbe manages to survive the trip, chances
are that they wouldn't have made it anyhow... although I agree it would be nice
to be able to study them.

IMHO, the Galileo probe is far more likely to give us evidence for/against
the existence of Jovian microbial life than to wipe it out, tho' from your posting
I gather you agree with this viewpoint anyway.

Peter Scott ([e-mail])

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

Date: 26 Sep 89 12:57:32 GMT
From: mcsun!ukc!icdoc!syma![e-mail]  (Nick Watkins)
Subject: Re: space news from Aug 14 AW&ST

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

>STS-28 deploys advanced imaging spysat Aug 8.  Satellite is an upgraded
>version of the KH-11 [i.e. the KH-12?  not clear].

The "better means to transmit its images to US military field units at
sea or in such places as West Germany" (under the TENCAP programme) and
the "greater maneuvering capability"  were both advertised properties
of the KH-12, so it probably is a KH-12.  The name Strategic Response
System is new to me though.

>  This bird is at a lower
> altitude than the Lacrosse launched last year, and was deployed using the
> arm, which Lacrosse wasn't.

Article in fact says it was other way round.

Interestingly, AW&ST says 1988 Titan 34D launch from VAFB might have
carried a KH 11, echoing the recent posting from John Pike. This was the
one originally labelled as an SDS, though AW&ST had no item on it at
all as far as I know.

>"Where is D.D. Harriman now,   |     Henry Spencer at U of Toronto Zoology
>when we really *need* him?"    | uunet!attcan!utzoo!henry [e-mail]

OK. So I'm ignorant. Who is D.D. Harriman? Meanwhile, I was beginning to
believe that Henry's summaries might be the on-line version of AW&ST
mentioned in "2010" when I noticed a recent ad therein, which says the
whole text is available on line to suitably rich subscribers. Same goes
for some other McGraw Hill trade journals.

Nick
--
Nick Watkins, Space & Plasma Physics Group, School of Mathematical
& Physical Sciences, Univ. of Sussex, Brighton, E.Sussex, BN1 9QH, ENGLAND
JANET: [e-mail]   BITNET: [e-mail]

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

Date: 27 Sep 89 17:43:09 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: Risk of NOT launching Galileo

In article <[e-mail]> [e-mail] (Steve Willner) writes:
>From article <[e-mail]>, by [e-mail] (Tom Neff):
>> It's a nice point that scratching Galileo could cost us weather
>> knowledge, but Mission To Earth will do it better.
>
>Are you sure?  Presumably the same basic physics govern the weather
>systems on the two planets, but the conditions are utterly different.
>The way to verify models - which is all we have - is to test them on
>systems that are as different as possible.  Thus I expect that we will
>learn things by studying Jupiter's weather that we would never learn by
>studying only Earth's.  Certainly there is considerable _risk_ that this
>is true.

This and another followup suggest we'll learn things from Jupiter's
weather that we can't learn by studying our own.  Granted.  But this was
not quite the issue.  Will we learn materially more about OUR OWN
weather from studying Jupiter than we can from studying Earth?  I have
my doubts.  And if I have my doubts, you can bet that any Congressman
who has heard of "Mission to Earth" would have his.  I would appreciate
hearing from actual atmospheric scientist who can point to an open
meteorological conjecture for which Galileo looks more promising than
Mission to Earth.

For what it's worth I do want Galileo to go, but bogus justifications
can come back to haunt us, as the Space Shuttle ("it'll cut costs to
orbit by a factor of 10") demonstrates.
--
"NASA Selects Deck Chair Arrangement For Space  \_/  Tom Neff
Station Titanic" -- press release 89-7654       \_/  [e-mail]

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

Date: 27 Sep 89 19:21:23 GMT
From: [e-mail]  (Michael C Nolan)
Subject: Re: Time Urgent: Voyager movies Oct 2 on satellite or tape

In article <[e-mail]> [e-mail] (Bill Higgins-- Beam Jockey) writes:
>Here's a press release I just received from JPL:
>The recently completed Neptune Encounter Highlights tape will be transmitted
>over NASA-Select on Monday, October 2.
>
>DATE/TIME:
>
>October 2  1:00-1:29 PM Eastern Time, 9:00-9:29 AM Pacific Time
            ^^^^^^^^^                  ^^^^^^^^^

Um, These are not at the same time.  Anybody know which one is right?

-Mike

[e-mail]
[e-mail]

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

Date: Wed, 27 Sep 89 14:58:05 PDT
From: Peter Scott <[e-mail]>
Subject: Re: Mars Mission ship design

In article <[e-mail]> [e-mail] (Kevin Bagley) writes:

> 2)     Anybody know the estimated mass of Freedom. Using Lunar gravity
>        assist, how much fuel/thrust would be needed. Don't forget the
>        return home requirements.

A figure I have seen for "mass of assembly consumables", whatever *that* is,
is 40,978 lb.  I have also seen a figure of cost-to-orbit of $3,000/lb in
1988 currency.

Peter Scott ([e-mail])

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

Date: 27 Sep 89 15:05:42 GMT
From: usc!henry.jpl.nasa.gov!elroy.jpl.nasa.gov!jpl-devvax![e-mail]  (Lee Mellinger)
Subject: Re: Risk of NOT launching Galileo

In article <[e-mail]> [e-mail] (Tom Neff) writes:
:It's a nice point that scratching Galileo could cost us weather
:knowledge, but Mission To Earth will do it better.
:--

Not necessarily true, Jupiter and the other planets with atmoshperes,
give us data points on atmospheres that cannot be gotten any other
way, the conditions are different, allowing the comparison of models
to test the underlying assumptions.  In fact, the planetary
exploration program has spawned an entirely new academic discpline,
Comparative Planetology.

Lee

|Lee F. Mellinger                 Caltech/Jet Propulsion Laboratory - NASA
|4800 Oak Grove Drive, Pasadena, CA 91109 818/393-0516  FTS 977-0516
|{ames!cit-vax,}!elroy!jpl-devvax!leem  [e-mail]

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

Date: 27 Sep 89 15:48:34 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Re: NIMF proposal from Martin Marietta

In article <[e-mail]> [e-mail] (Doug Price) writes:
>
>I talked to Zubrin at the Space Development Conference about the level of
>radioactivly that could be expected in the NIMF reactor at its return to earth
>orbit, and he said basically that the reactor operates for such a short
>period over its entire life that its total residual radioactivity amounts
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>to the tens of curies.  The worst case scenario of an uncontrolled burn-up
>in earth's atmosphere after one or more Martian missions would be trivial
>(though, of course, there are plenty of people out there that would find
>this concept horrific as well.)

How is total residual radioactivity defined?

Plugging in numbers from the graph in Segre (Nuclei and Particles, 2nd
ed., page 594), the energy (as beta or gamma rays) produced by fission
products, per joule of heat produced at the time of fission, is
roughly

    Time since fission    watts/joule
    -----------------------------------
       1 day          1.5e-8
      10 days          1.0e-9
     100 days          5.0e-11
     900 days          5.0e-12

Operating the reactor for ten minutes at 1000 MW(thermal) produces
6e11 joules of heat, so residual heat at 1, 10, 100 and 900 days is
roughly 9 kW, .6 kW, 30 W and 3 W, respectively.  At 1 MeV/decay
(say), 3 watts is about 170 curies.

NERVA with ET propellant production sounds ideal for asteroid
retrieval to earth orbit -- lots of thrust if you have the volatiles,
and it could insert into earth orbit without aerocapture.  The reactor
could also serve as a heat source to cook volatiles out of the
asteroids.

I have a hard time understanding this Mars fixation.  There are lots
of smaller planetoids closer to Earth, without deep gravity wells.
Let's visit some of them first.

    Paul F. Dietz
    [e-mail]

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

Date: Wed, 27 Sep 89 10:13:36 PDT
From: Peter Scott <[e-mail]>
Subject: YAHSS (Yet Another Henry Spencer Signature)

jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer) writes:

>"Where is D.D. Harriman now
>when we really *need* him?"

Hmm... has anyone tried pitching the commercial space program to Donald Trump?
I was just in Manhattan and visited Trump Tower.  It's obvious the guy isn't
afraid to spend money...  ah, I can see it now... the *real* "Trump Shuttle"...

Peter Scott ([e-mail])

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

Date: 27 Sep 89 08:30:14 GMT
From: mcsun!ukc!edcastle![e-mail]  (A J Cunningham)
Subject: Re: Plutonium in space (was Risk of NOT launching Galileo)


    Greenpeace did an article in their newsletter which showed the
location of all lost nuclear reactors and warheads in the world's
oceans. There are about fifteen in all including a hydrogen bomb that
rolled off the deck of an aircraft carrier off Japan. Given that most of
the world's plutonium is in the hands of the military and the odds of a
B52 crashing and spraying plutonium all over the ground (as one did in
Spain  when it collided with its tanker aircraft) are far greater than
any accident involving a space mission (Are bombs built to withstand
crashing better than RTGs?) surely this would be a better subject for
lawsuits and column inches in the newspapers?
        Tony
        "Furthur!"

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

Date: 28 Sep 89 03:33:13 GMT
From: ibmpa![e-mail]  (nick szabo)
Subject: Re: Alternative Space Goals, Anyone? (was Re: SpaceCause)

In article <[e-mail]> [e-mail].U
UCP (Brian Yamauchi) writes:
>In article <[e-mail]> [e-mail] (Nick Szabo) writes:
>>In article <[e-mail]> [e-mail] w
rites:

>>>The closest thing to that (if you don't have NSS' position statements)
>>>That is to say, SPACE STATION,
>>>MOON, and MARS are the three main goals.
>>
>>Ah, The Plan.


>[What alternatives do we have to The Plan?]
>More funding for robotic space probes would definitely help both space
>science and space exploration,

I quite strongly agree with this.  We also need funding for basic R&D
to create working models of MPD engines, laser propulsion, optical space
communications, nuclear electric power, etc.  BTW Henry those are just
examples not necessarily the most important ones.  :-)

> and companies like AMROC, SSI, and
>OSC/Hercules seem to be on the right track towards providing low-cost
>access to orbit.

>
>These are important first steps, but what's next in the Alternative
>Agenda for space development?

Who knows?  The purpose of the first step is to _explore_ the diverse range
of possibilities.  Some will turn up empty, and some will bring riches.  We
can't predict that now, so it is not only useless, it is damaging, to plan
for it.

We can _speculate_, however.  Here is my favorite: we discover concentrated
ores of rare but valuable isotopes on Io, the most differentiated body so
far discovered in the solar system.  We bypass the Moon and Mars altogether,
creating the first permanent human space settlement around Jupiter.  We use
tethers on Metis to draw terrawatts of power* for industrial uses (including
the tricky mining operations on Io!).  We steer asteroids from the Main Belt
into orbit around Jupiter, and use Metis power to build habitat structures.

Of course this is far fetched.  It is quite different than The Plan, and
thus a heresy.  But not one proponent of The Plan can demonstrate that this
scenario is any less probable or useful than the Moonbase/Mars scenario.

My own guess is that comets and asteroids are the most useful, followed by
the Galilean system and Mars, with the Moon being a mere import-dependent
tourist trap.  But none of us have enough information to try to decide
this now.

"Anyone who attempts to generate random numbers by
deterministic means is, of course, living in a state
of sin."
                        John von Neumann


* Metis orbital power proposal due to Paul Dietz.  The idea is to use
tethers to extract the power of a tiny portion of Metis' orbital velocity
through Jupiter's very large magnetic field.


--
--------------------------------------------
Nick Szabo
uunet!ibmsupt!szabonj
These opinions are not related to Big Blue's

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

End of SPACE Digest V10 #103
*******************