Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v08/v8_276.txt

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Date: Sat, 16 Jul 88 01:06:58 PDT
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Subject: SPACE Digest V8 #276

SPACE Digest                                      Volume 8 : Issue 276

Today's Topics:
               Re: SPACE Digest V8 #255
                 Space Digest
     Re: advance space news from June 6 AW&ST -- Pegasus!
             Re: News on Shuttle oxidizer
       Re: Hawaiian spaceport? (Was: Re: SPACE Digest V8 #221)
                 Re: Pegasus
     Re: advance space news from June 6 AW&ST -- Pegasus!
     Re: advance space news from June 6 AW&ST -- Pegasus!
            Dukakis vs private spaceflight
               Re: Cometesimals
----------------------------------------------------------------------

Date:         Fri, 17 Jun 88 11:48:21 EDT
From: Dess-DEMON-a <[e-mail]>
Subject:      Re: SPACE Digest V8 #255

Introducing! A new line of unisex skintight space suits, for men, women & those
that are undecided.

     Hey, question:  What contraception does a martian use? And would
their antennae stick up/out?  For that matter, with all that skintight
fasion going around in space, what contraception would space people use?


Q:  Does anyone REALLY believe that earthings will be able to survive in
    space stations in various locations? Just a thought... (Do you think
    we'll have an orbital station around Uranus?  Who'd want to live there?
    It's SO COLD!)

From Dess & Jimbo (like Rambo, his wife Bimbo, & his dog Spot-bo)
                   Sung to "THE JETSONS"
Acknowledge-To: <R2CDN@AKRONVM>

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

Date:     Fri, 17 Jun 88 21:24 AST
From: <[e-mail]>
Subject:  Space Digest

Please send me Volume 8, Issues 230, 241 and 247. No one who has access
to bitnet here in Fairbanks seems to have any of these issues. Are you able
to tell what happened to them please? Thanx in advance for any information
you are able to offer      gf

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

Date: 18 Jun 88 13:35:27 GMT
From: phri![e-mail]  (Roy Smith)
Subject: Re: advance space news from June 6 AW&ST -- Pegasus!

[e-mail] (Henry Spencer) writes:
> Pegasus, a winged three-stage design that will be air-launched from a B-52.
> [...] Payload is 600lb into low polar orbit, 900 into low equatorial orbit.

    For the benefit of us interested-but-ignorant observers, can you give
me some idea of how useful a 600-900 pound (still no metric!) payload is?
What does a typical commsat weigh, for example?  Or a typical package of
scientific instrumentation?  Or (God forbid), a typical military payload
(warhead, spysat, whatever).  Is there even such a thing as "typical"?

    Would such a delivery system be useful for making small emergency
shipments to a permanent space station ("Houston, we, uh, seem to have loaded
our camera wrong and wasted all our film; think you could Pegasus up another
few rolls before this comet goes out of range?").  Sounds like putting one of
these up might be a lot faster than waiting for the next scheduled shuttle.
--
Roy Smith, System Administrator
Public Health Research Institute
455 First Avenue, New York, NY 10016
{allegra,philabs,cmcl2,rutgers}!phri!roy -or- phri![e-mail]

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

Date: 17 Jun 88 14:43:40 GMT
From: mcvax!ukc!its63b![e-mail]  (ERCF08 Bob Gray)
Subject: Re: News on Shuttle oxidizer

In article <[e-mail]> [e-mail] (Peter Scott) writes:
>From the JPL UNIVERSE, June 10:
[...]
>The production amount of 40 million pounds per year is still less than is
>needed by all users, including NASA, Department of Defense, and commercial.
>
>There will be an allocation process developed among the DoD, NASA and the
>commercial users.

This may seem a very strange suggestion to some people, but why
don't they buy the chemical on the international market? I am
sure there must be other chemical plants capable of supplying
what is needed until the new US production capacity is built.
    Bob.

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

Date: 17 Jun 88 14:34:10 GMT
From: mcvax!ukc!its63b![e-mail]  (ERCF08 Bob Gray)
Subject: Re: Hawaiian spaceport? (Was: Re: SPACE Digest V8 #221)

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>Yeah, Cape York!  The biggest thing wrong with Hawaii is that it's in the
>wrong country.

For the latest on the Cape York spaceport, look at "New Scientist"
dated 12 May. pages 36 and 37.

There are two rival groups of companies investigating seting
up a spaceport on the cape york penninsula.

The Cape York Space Agency is a group of 64 companies
appointed by the Queensland Government to oversee the project.

The Australian Space Group is carrying out it's own study.

Two sites are being considered.the west coast site at Weipa
already has harbour facilities and makes polar orbits
easier. A site on the east coast makes equatorial orbits
easier, launches directly over the Pacific, and has the
added tourist attraction of the Great barrier Reef.

The Soviet space authority, Glavkosmos, is said to want
to install a Proton launcher on the site to get round
restrictions on exporting American technology to the
Soviet Union, if the USA can be persuaded that Australia
is neutral ground.

Does anyone in Australia have any more information? There
was a posting from there last year about the project but
nothing since then.
    Bob.

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

Date: 18 Jun 88 17:30:20 GMT
From: [e-mail]  (Paul F. Dietz)
Subject: Re: Pegasus

In article <[e-mail]> [e-mail] (D. Starr) writes:
>>In article <[e-mail]>, [e-mail] (David Smith) writes:
>>                 ...it's doubly surprising to me that,
>>with all the oddball, exotic, and trivial stuff that gets discussed in
>>this forum, Pegasus hasn't stirred more comment.
>
>What's the surprise?  At $6 million to launch 850 lbs (over $7000/lb), the
>per-pound cost of Pegasus will be: ... That ain't too exciting.

The advantage of the Pegasus is presumably the much lower amount
of red tape needed to launch something, and the faster turn around
time.  The delay and hassle of launching a 600 pound payload on
the shuttle is considerable, even though it doesn't show up
in the raw dollars/pound to orbit figures.

I also suspect Pegasus will have a steeper learning curve than its
larger competitors, since it is relatively simple and per unit cost
is lower.

Cynically, a market is guaranteed because the thing is air
launched.  That means it would still be useful in a war after
fixed launcher sites have been destroyed.  By the way: how much
does a nuclear reentry vehicle weigh?

    Paul F. Dietz
    [e-mail]

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

Date: 18 Jun 88 17:53:31 GMT
From: b.gp.cs.cmu.edu![e-mail]  (Ralf Brown)
Subject: Re: advance space news from June 6 AW&ST -- Pegasus!

In article <[e-mail]> [e-mail] (Roy Smith) writes:
}[regarding Pegasus launch:]  Sounds like putting one of
}these up might be a lot faster than waiting for the next scheduled shuttle.

You bet it would be faster than a shuttle launch!  With proper procedures, it
should be possible to emergency-launch one within an hour of the word "GO".
If you can't get one up within 24 hours, there's something wrong with your
procedures (this assumes, of course, that you have one on hand, as well as
its payload).

The shuttle's rollout from the VAB to the pad alone takes several hours, not
to mention the army of techs to check it out, over, inside, out, etc.

--
{harvard,uunet,ucbvax}!b.gp.cs.cmu.edu!ralf -=-=- AT&T: [phone] (school)
ARPA: [e-mail] |"Tolerance means excusing the mistakes others make.
FIDO: Ralf Brown at 129/31 | Tact means not noticing them." --Arthur Schnitzler
BITnet: RALF%B.GP.CS.CMU.EDU@CMUCCVMA -=-=- DISCLAIMER? I claimed something?

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

Date: 19 Jun 88 08:26:56 GMT
From: agate![e-mail]
Subject: Re: advance space news from June 6 AW&ST -- Pegasus!

In article <[e-mail]>, henry@utzoo (Henry Spencer) writes:
>      The June 6 issue just arrived, and the lead story is the
>best news in years.  So here's a special out-of-sequence report.]
>
>New launcher:  Pegasus, a winged three-stage design that will be air-
>launched from a B-52.  It's a joint effort of Orbital Sciences and
>Hercules, with Rutan building the wing.  Payload is 600lb into low
>polar orbit, 900 into low equatorial orbit.
>
>Now the GOOD news...  Pegasus is 100% private, although the first customer
>is DARPA.  Total funding is $40-45M, about a third of it already spent.
>It has been underway about one year, they are already bending metal on
>the first one, and it flies NEXT YEAR!  There is already a lineup of
>customers.  Cost to orbit will be half or less that of similar-sized
>payloads on existing launchers.
>

Private development is not new-- Space Services Inc. of Houston has
designed, built and *flown* the Conestoga using private funds.  And they
are offering their launchers to DARPA on a strictly commercial basis.
Furthermore, it is an exaggerated claim that the $10M launch price (or
is it expected launch price) of the Pegasus is half that of the
competition.

If DARPA commits to buying launches on a vehicle which is still in the
development stage, how is that significantly different from them paying
for development?  What happens when there are cost overruns and
production delays?  The article also raises questions about possible
hidden subsidies: How much are OSC and Hercules paying for use of the
NASA B52?  How much are they paying for computing at Ames?

There are certainly advantages to a B52-launched vehicle, and Henry
mentioned several.  But there are still large obstacles to be overcome.
Hercules and OSC claim that they will develop, build and certify not
one, not two, but three new motors with $45M, and in one year.  I hope
so!  How is Hercules doing on its more luxuriously funded motor
development programs?

One of the more important aspects of this article is the tense.  The
Pegasus will cost less than $10M per launch.  The Pegasus will fly next
summer, even though none of the three motors has yet been built.  The
Pegasus will only cost $45M to develop.  The Pegasus will succeed
because the project needs only five to six missions annually to remain
viable.

Hercules and OSC have far to go before this project amounts to much more
than the inflated claims of a marketing campaign.  I sincerely hope they
succeed, and wish them luck.
--
--

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

Date: 19 Jun 88 02:30:10 GMT
From: mnetor!utzoo![e-mail]  (Henry Spencer)
Subject: Dukakis vs private spaceflight

(This started out as a reply to private mail, which is why you haven't
seen the quoted passage...  But the path I tried to use failed, and
it occurred to me that it might be of more general interest anyway.)

> [Dukakis supports industry]  ... My expectation would be that
> private space industries would do as well under Dukakis as Bush.
> Have you heard or read something specific that contradicts this, or
> is it just a general impression?

I have nothing particularly specific to go on, no.  I haven't been
following Dukakis's position in particular, since I don't get to vote
in US elections. :-)  The problem is that there are strong consituencies
within the government -- NASA and the USAF -- that prefer government
control rather than free enterprise.  They've been doing their level
best to obstruct private spaceflight, with limited success of late since
the Reagan administration has a firm ideological commitment to private
industry.  I'm not so much worried that Dukakis would be anti-private-
spaceflight -- it would be a difficult position to justify -- as that
he won't be sufficiently pro-private-spaceflight to back the fledgling
space industries when they come to a showdown against the big, powerful,
entrenched bureaucracies.  The anti-private-spaceflight tendency is
already there within the government; Dukakis needs to make an active
effort to counter it, and I'm not sure he will.
--
Man is the best computer we can      |  Henry Spencer @ U of Toronto Zoology
put aboard a spacecraft. --Von Braun | {ihnp4,decvax,uunet!mnetor}!utzoo!henry

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

Date: 20 Jun 88 06:10:35 GMT
From: jumbo![e-mail]  (Jorge Stolfi)
Subject: Re: Cometesimals


>   PAUL DIETZ: Cometesimals hitting the moon would deliver an enormous
>   amount of water over geologic time, so even if one molecule in
>   a million is trapped, there would still be a lot there.

The latest issue of _Science_ (10 Jun 88, p.1403) has an article on
Louis Frank's cometesimals.  It seems the theory now gained two
independent (if rather dubious) supporting pieces of evidence.

Piece #1 is that the dark spots that are attributed to the cometesimals
have been found also in ultraviolet images of the Earth taken by a
Swedish satellite (they had to call it "Viking", just to confuse
everybody --- why couldn't they call it "Haggar" or "Bergman" or
"Volvo"?).  Apparently each spot covers only half a dozen pixels or so,
and some investigators who have analyzed the images claim the spots are
mere artifacts of the imaging system.

Piece #2 is the possible detection of cometesimals by C.  Yates from
JPL, using a CCD camera on the Space Watch Telescope at Kitt Peak.
He cleverly pointed the telescope at a random spot in the sky and swept
it in a random direction at a random speed, thus precisely matching the
random motion of the hypothetical cometesimals in their random orbits.
(For a more precise but less amusing description of the technique, go
read the _Science_ article yourself).  The result was a handful of 18th
magnitude tracks (1 or 2 pixels wide, up to 20 pixels long).
These tracks are said to closely match the predicted appearance and
motion of cometesimals 3 to 4 meters in diameter halfway between the
Earth and the Moon.  The article says that Yates was able to eliminate
other obvious explanations, such as meteors, fireflies, cosmic rays,
and rocket debris.  However, the images haven't been checked by other
astronomers yet (although three of them are reproduced in the article).

                             -xox-

Apparently, one of the most troublesome aspects of the theory is the
assumption that cometesimals are largely made of water ice.
Halley's water starts to evaporate at Jupiter's distance, producing a
visible coma; yet the cometesimals in the Earth's neighborhood cannot
do that, or we would see them.  Also, the dryness of Venus is hard to
explain given the huge amount of water that would be brought in by the
cometesimals, which would be enough to fill all the Earth's oceans over
geologic time.

My question is, what is the evidence that the cometesimals contain any
water at all?  Here from my armchair it would seem that any soot-black
cometesimal only 12 meters across in the Earth neighborhood should have
been baked dry by now.  Its surface should be hot enough to fry an egg
even if averaged by rotation, right?  Is it possible that a few meters
of "comet dust" can insulate an icy core long enough for it to reach
the Earth intact?  ("Long enough" may be a couple of years if the
cometesimals are new arrivals from outer space, or saganillions of
years if they have always been in our neighborhood.) Besides, is it
known how opaque "comet dust" is to longwave infrared radiation?
(Graphite is rather transparent, isn't it?) also, what is the current
official guess for the thickness of Halley's dry dust cover?

I believe that one reason for assuming that cometesimals are mostly
water is that they must disintegrate before they reach the lower
atmosphere (otherwise we would see them as meteors).  This rules out
rocks and pebbles as common constituents of the cometesimals.
Does it also rule out cometesimals entirely made of dry and
fluffy "comet dust"?  Note that this dust need not be silicates; it may
be carbon soot or a more exotic (organic?) substance.  (Halley's dust
includes a high proportion of "organic" compounds, and anyway Frank's
cometesimals may or may not be Halley's relatives).

Finally, could the dark spots in the UV pictures be produced by
vaporized "comet dust" of suitable composition, instead of H2O?
In that case, would we still need 100 tons of dust to make one spot?

  National Enquirer mind wants to know,
                                             +-----------------+
    Jorge Stolfi                             |     DANGER      |
    DEC Systems Research Center              |  FALLING STARS  |
    [e-mail], ...!decwrl!stolfi    | NEXT 5e11 MILES |
                                             +-----------------+

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DISCLAIMER: Don't look at me that way --- I didn't put them up there.

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

End of SPACE Digest V8 #276
*******************