Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_5/V15NO542.TXT

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Date: Sun, 13 Dec 92 05:11:37
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #542
To: Space Digest Readers
Precedence: bulk


Space Digest                Sun, 13 Dec 92       Volume 15 : Issue 542

Today's Topics:
             Casinissini Udergoed Intense Design  Review
               Cassini Undergoes Intense Design Review
          Cassini Undergoes Intensive Design Review (2 msgs)
             Crystal growth in space - Bad NASA economics
                       LANSAT satellite images.
                             liquid fuels
 No asteroid flybys (was Re: Cassini Undergoes Intense Design Review)
            Re: Cassini Undergoes Intensive Design Review
                   SR-1 (was Re: DoD launcher use)
                 STS-48 and "SDI": Oberg vs. Hoagland
                            Wither the ET?

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

Date: Sun, 13 Dec 1992 01:22:25 GMT
From: Henry Spencer <[e-mail]>
Subject: Casinissini Udergoed Intense Design  Review
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Ryan Korniloff) writes:
>Regarding the Titan probe - will it have a camra to take images of the
>landscape? ...

There is an imaging system of some sort -- I forget the details -- on
Huygens (the Titan probe that will fly on Cassini).

(My personal opinion is that the omission of this on Galileo's probe was
a mistake, although admittedly it would have taken a major redesign
because the probe's data rate is too low for imaging.)
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: Sat, 12 Dec 1992 09:53:18 GMT
From: Dan Tilque <[e-mail]>
Subject: Cassini Undergoes Intense Design Review
Newsgroups: sci.space,sci.astro,alt.sci.planetary

[e-mail] writes:
>     After flybys of Venus (twice), Earth and Jupiter as it loops
>around the sun to pick up energy, Cassini will arrive at Saturn
>in November 2004, beginning a four-year orbital tour of the
>ringed planet and its 18 moons. The Huygens probe will descend to
>the surface of Titan in June 2005.

Another game of cosmic billiards.  I assume that people are looking into
the possibility of asteroid flybys, aren't they?

---
Dan Tilque    --     [e-mail]

PS  And this time, someone remember to lube the HGA deployment gizmo...

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

Date: 12 Dec 1992 04:28:51 GMT
From: Zdzislaw Meglicki <[e-mail]>
Subject: Cassini Undergoes Intensive Design Review
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Ron Baalke) writes:
|> Cassini is also carrying a Titan probe which adds additional mass to the
|> spacecraft.

Could anyone sum up at this stage what is known about Titan and especially
about the question of a possible ocean there. I vaguely recall that some
time ago radio-ranging of Titan returned somewhat mixed signals in this
matter.

|> To
|> further complicate the situation, the U.S. do not have any launch vehicles
|> that are powerful enough to send Cassini on a direct trajectory to the
|> outer planets.

Right, can't the US build such a vehicle by then? Clearly, if any serious
space exploration is to continue a powerful vehicle like that will be
needed sooner or later anyway. What happened to the idea of nuclear
propulsion?

--
   Zdzislaw Gustav Meglicki, [e-mail],
   Automated Reasoning Program - CISR, and Plasma Theory Group - RSPhysS,
   The Australian National University, G.P.O. Box 4, Canberra, A.C.T., 2601,
   Australia, fax: (Australia)-6-249-0747, tel: (Australia)-6-249-0158

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

Date: Sun, 13 Dec 1992 01:28:04 GMT
From: Henry Spencer <[e-mail]>
Subject: Cassini Undergoes Intensive Design Review
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Zdzislaw Meglicki) writes:
>|> ... the U.S. do not have any launch vehicles
>|> that are powerful enough to send Cassini on a direct trajectory to the
>|> outer planets.
>
>Right, can't the US build such a vehicle by then?

Sure, if they tried.  But there's no money for it.

(It's not enough to strap something together.  Given that Cassini is another
bloated megaproject, and that it will be the only Saturn mission for several
decades unless Goldin can turn things around some, and that there is no
backup copy of the hardware, the Cassini mission planners would be crazy
to risk their bird on a brand-new booster; they want something well-proven.
Still could be done, but it does run up the bill.)
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: 12 Dec 92 18:37:29
From: Joseph Brenner <[e-mail]>
Subject: Crystal growth in space - Bad NASA economics
Newsgroups: sci.space

Thanks for typing in these excerpts.  If you hadn't done it,
I would have.

> What follows are some excerpts that match the overall
> authors' feelings that protein crystal growth in space has
> little economic advantage over Earth-bound growth.

I think this is a bit of an exaggeration (though not much).
Really they're saying that nothing that has *yet* been done
has justified the expense, and there needs to be some
careful thought about what should be done.  One way of
looking at this article is that it's an advertisement
directed toward biologists: they want them to submit their
unsolved protein crystal growth problems.  Still another way
of looking at it is that it's an ad for using the
Soviet-built facilities rather than the US systems.

All in all, I thought this article was unusually frank,
considering that the researchers are themselves engaged in
microgravity research.  Don't they know that they're
supposed to claim that everything is coming up roses?

Their names deserve to be recognized:

     Barry L. Stoddard
     Fred Hutchinson Cancer Research Center
     Seattle, Washington

     Roland K. Strong
     Division of Biology
     CalTech

     Anthony Arrott
     Payload Systems
     Cambridge, Massachusetts

     Gregory K. Farber
     Deptartments of Chemistry and Molecular Cell Biology
     Penn State

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

Date: Sat, 12 Dec 1992 19:59:58 GMT
From: Brian Dickens <bdickens@el_padre.mitre.org>
Subject: LANSAT satellite images.
Newsgroups: sci.space

Does anyone know where I can find information describing the format of
LANSAT satellite images?

Any help is appreciated...
-bdickens

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

Date: Sat, 12 Dec 1992 19:11:57 GMT
From: Dave Michelson <[e-mail]>
Subject: liquid fuels
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:
>-After the Challenger failure, NASA added a safety requirement that
>-nothing launched in by a space shuttle may use liquid fuels. That
>-means Cassini must use lower-energy solid rockets instead.
>
>I think you mean *cryogenic* fuels. Magellan, Galileo, and Ulysses all
>use liquid fuels.
>
>As I mentioned earlier, some of the post-Challenger Shuttle safety rules
>are being relaxed (following intensive review, of course). Perhaps this
>rule will eventually be one of them. Henry has indicated he would favor
>such a change.

The major problem with cryogenic fuels is that they boil off and the
gas must be vented.  This becomes a real problem if the upper stage
is located inside the shuttle cargo bay.  The modifications that must
be made to the shuttle are non-trivial.

--
Dave Michelson
[e-mail]

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

Date: 12 Dec 92 21:05:29 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: No asteroid flybys (was Re: Cassini Undergoes Intense Design Review)
Newsgroups: sci.space,sci.astro,alt.sci.planetary

In article <[e-mail]>, [e-mail] (Dan Tilque) writes:
> [e-mail] writes:
>>     After flybys of Venus (twice), Earth and Jupiter as it loops
>>around the sun to pick up energy, Cassini will arrive at Saturn
>>in November 2004, beginning a four-year orbital tour of the
>>ringed planet and its 18 moons. The Huygens probe will descend to
>>the surface of Titan in June 2005.
>
> Another game of cosmic billiards.  I assume that people are looking into
> the possibility of asteroid flybys, aren't they?

Nope.  It was announced in *Aviation Leak* that the policy of seeking
asteroid flybys has been dropped to keep costs down on Cassini. :-(

Bill Higgins                           | In the distant future,
Fermi National Accelerator Laboratory  | nuns will be bartenders
Bitnet:      [e-mail]       | aboard starships
Internet:  [e-mail]       | and Sternbach paintings
SPAN/Hepnet:      43011::HIGGINS       | will hang on every wall.

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

Date: Fri, 11 Dec 1992 16:25:54 GMT
From: Ross Cunniff <[e-mail]>
Subject: Re: Cassini Undergoes Intensive Design Review
Newsgroups: sci.space

[e-mail] (Hayim Hendeles) writes:
>>     After flybys of Venus (twice), Earth and Jupiter as it loops
>>around the sun to pick up energy, Cassini will arrive at Saturn
>>in November 2004, beginning a four-year orbital tour of the
>>ringed planet and its 18 moons. The Huygens probe will descend to
>>the surface of Titan in June 2005.
>Pardon my asking an ignorant question, but I can't understand why it
>should take 7 years to get to Saturn. When Voyager went to Jupiter and
>Saturn, it took (if I recall correctly) 4 years and a Jupiter flyby to
>make it to Saturn. Here, you are using 4 flybys, and it's taking you 7
>years!

You have to consider that Cassini (and Galileo) are *HUGE* interplanetary
probes.  Voyager was a lightweight - a Titan II launch sent it on a direct
orbit to Jupiter, and then it used a gravity assist to Saturn and beyond.

Now, Galileo WAS originally slated for a direct-to-Jupiter launch aboard
a Centaur upper stage; however, post-Challenger safety requirements mandated
an IUS (originally, Interim Upper Stage, now Inertial Upper Stage :-) as
the final boost for it.  An IUS is not nearly energetic enough for a direct
route, so they went for the Venus-Earth-Earth-Jupiter trajectory.  It
looks like Cassini has similar weight problems, and so they're going
Venus-Venus- Earth-Jupiter-Saturn.

>Thanks for your help.

You are quite welcome.

>HAyim Hendeles

Ross Cunniff
Hewlett-Packard Graphics Software Lab
[e-mail]

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

Date: Sun, 13 Dec 1992 01:20:13 GMT
From: Henry Spencer <[e-mail]>
Subject: SR-1 (was Re: DoD launcher use)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>>Using DC itself as a recon platform
>>seems like serious overkill,
>
>Not DC itself. DC simply launches the satellite.

Actually, why not DC itself?  It's the ultimate recon aircraft:  pictures
of any location in the world (weather permitting) within an hour of takeoff,
operation far beyond conventional SAM envelopes, and no need for vulnerable
and costly forward operating bases.  You pay for this, of course, in very
high fuel consumption and high wear-and-tear costs (more expensive vehicle
with a shorter lifetime).  Large-scale use would perhaps be too expensive,
but using a squadron of suitably-equipped DCs -- call it, say, the SR-1 --
as the high end of a spectrum of recon aircraft is not ridiculous.

As for it being "serious overkill", lots of problems are solved that way.
When costs of general-purpose solutions fall enough, the special-purpose
solutions wither and die, or are restricted to particularly-demanding
niche markets, because they're no longer worth the trouble.  Architects
from Babylon to Chartres sweated to develop the arch as a way of supporting
things, but we do almost all our structures with post-and-lintel -- the
stone-age precursor of the arch -- because with modern materials, it works
just fine and is a lot less hassle for most jobs.  There is an entire
computer in your *keyboard*, spending its whole life doing nothing but
waiting for your keystrokes and passing them on to the machine that does
the real work... because special-purpose keyboard-encoder chips are no
longer worth designing.  Nuclear propulsion for aircraft once looked like
the only way to get very long range, but in the time needed to half-
solve its problems, conventional jet engines improved so spectacularly
(the unrefuelled cruising range of a B-52H, with early-1960s engine
technology, is *twelve thousand miles*) that it was obsolete before it
ever powered an aircraft.

Nobody will build hypersonic recon aircraft if spaceships are already
available and cheap enough.  The SR-1 may not be good enough, but the
SR-2 or SR-3 probably will be.
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: 12 Dec 92 08:26:07 GMT
From: [e-mail]
Subject: STS-48 and "SDI": Oberg vs. Hoagland
Newsgroups: sci.skeptic,sci.astro,sci.space,alt.alien.visitors

Robert McGrath writes:

>You'd probably even like Phil Klass if you met him, Barb.  :-))

Well, guess what?  I _have_ met him at the MUFON conference in Albuquerque

last summer.  Did I like him?  Well, I respect his opinion, but I can't
see us hanging out for any extended period of time.  :)

All groups I belong to/think highly of?  Well, let's see, I was in 4-H as
a kid, I think highly of the Boy Scouts, Mothers Against Drunk Driving and
the ASPCA...this would take an awfully long time to continue...

Geez, people, why all this flaming?  WHY CAN'T WE JUST LIVE TOGETHER???

Peace on earth, goodwill toward men (and women),

Barb

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

Date: Sun, 13 Dec 1992 00:05:47 GMT
From: Josh 'K' Hopkins <[e-mail]>
Subject: Wither the ET?
Newsgroups: sci.space

I just finished reading a friend's copy of the SSI's 1985 "Report on Space
Shuttle External Tank Applications" which left me both very impressed an a tad
depressed.

The document is something like 150 single sided pages of things to do with
spare ETs and Aft Cargo Carriers.  While I've always been a little skeptical
of the feasability of major modifications on orbit there are a number of very
good, practical ideas in there.  I know that NASA did take a more friendly
attitude to ET development a few years ago and the concepts even made it into
Business Week.  What happened?  Is development still chugging along somewhere
or is ET use to remain forever a dream?  Did the SOFI (Spray On Foam Insulation)
prove fatal to orbital use or did the normal economic and political hurdles
kill the companies that wanted to work on this?

[Note:  I thought about calling the post "ET Phone home" but figured that would
be both too corny and too confusing.  It would have fit the nature of the post
perfectly though.]
--
Josh Hopkins                                          [e-mail]
                        Ho^3     !=L

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

End of Space Digest Volume 15 : Issue 542
------------------------------