Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V10_0/V10_032.TXT

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Subject: SPACE Digest V10 #32

SPACE Digest                                      Volume 10 : Issue 32

Today's Topics:
           JPL address for ordering VOYAGER images.
             Re: Galileo Mission
         Re: Economies of Scale in Launchers
          Voting via taxes and other 3&*%^#!
             Re: Voyager: Tape recorder?
     Re: Galileo Jovian atmospheric probe -- is it sterilized???
              Pegasus Status - 31 Aug 89
     Re: Galileo Jovian atmospheric probe -- is it sterilized???
             Re: Message on Mars
     Re: Galileo Jovian atmospheric probe -- is it sterilized???
               Exotic Thrusters
             Re: Magnum snoopsat
              Re: Mars "face" image data
             Re: Neptune on the Boobtube
             Tracking Military Satellites
----------------------------------------------------------------------

Date: 31 Aug 89 15:22:44 GMT
From: wrksys.dec.com![e-mail]  (CUP/ASG, MLO5-2/G1 6A, 223-3283)
Subject: JPL address for ordering VOYAGER images.


        The following address is for ordering spacecraft images and
    other reference material from the Jet Propulsion Laboratory:

    Public Relations - JPL
    4800 Oak Grove Drive
    Pasadena, CA 91109

        I hope this will be useful to those of you looking for images
    of the Neptune system from VOYAGER 2.

        Larry Klaes  [e-mail]
             or - ...!decwrl!wrksys.dec.com!klaes
                 or - [e-mail]

        EJASA Editor, Astronomical Society of the Atlantic

             N = R*fgfpneflfifaL

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

Date: 31 Aug 89 18:42:32 GMT
From: b.gp.cs.cmu.edu![e-mail]
Subject: Re: Galileo Mission

In article <1050400001@cdp>, [e-mail] wrote:
 >to Jupiter. Galileo will be powered by 50 pounds of plutonium.

I keep hearing 47 and 50 POUNDS of plutonium (so far only from opponents of
launching the Pu).  I can believe that the *RTGs* weigh 50 pounds, but 50
pounds of Pu???  That sounds way off.

Does anybody have the real figures on this?

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

Date: 31 Aug 89 18:18:54 GMT
From: [e-mail]  (Terry Hancock)
Subject: Re: Economies of Scale in Launchers

In article <[e-mail]> [e-mail] (Bob Pendleton) writes:
>From article <[e-mail]>, by [e-mail] (Bob Campbell):
>>> Nope, high molecular weigth exhaust is better in a high pressure
>>> environment.  That is why there are solid fuel strap ons on so many
>>> boosters. In a vacuum you want the lowest possible weight exhaust.
>>>
>>>        Bob P.
>>
>> Are we confusing high thrust with efficiency?
>
>Could be. I don't claim to be an expert.
>
    I would like to interject that right after launch, high
thrust DOES mean higher efficiency.  Just to prove this, ask yourself
why Ion drives are useless as launchers.  It's simple -- they don't
produce enough thrust to even balance their weight in a 1 gee field,
much less accelerate anything.
    Similarly, high thrust engines, which generate high accelerations
soon after launch are more efficient than low thrust engines (of the
same specific impulse).  Consider two launchers, of the same specific
impulse, one which accelerates at two gees and another which accelerates
at eleven gees.  The first one is wasting 1/3 of its fuel to support
its weight, the second only 1/12 -- so clearly you can afford to lose
some specific impulse in order to gain more thrust and be more
efficient.
    This only holds for straight verticle flight, of course, and
only for a short while after launch -- but then, that's what the first
stage is for (on a conventional launcher, Pegasus uses slightly different
physics, for example).


*********************************
Terry Hancock
[e-mail]
*********************************

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

Date: 31 Aug 89 14:24:22 GMT
From: unmvax!deimos.cis.ksu.edu!cveg!hcx![e-mail]  (6079 Smith James)
Subject: Voting via taxes and other 3&*%^#!


In article <[e-mail]>, [e-mail] writes:
> >From: eplrx7![e-mail]  (leipold)
> >$1.  (As a matter of fact, I think allowing people to vote with their
> >taxes would be a good idea.  Let Congress and the IRS make up forms so
> >you can figure how much you owe, but then _you_ decide what percentage
> >of what you owe goes to what part of government.  But I digress from
> >sci.space...)

Neat idea.  Pretty soon we'd spend 70% of the budget on Social Security,
25% on Welfare, 4% on defense, and maybe .00001% on space.  If you let
people vote themselves a free lunch, they'll take it.

>     Another good statistic is that Americans spent $17G on entertainment
> last year!  People who say space program money would be better spent on
> <insert worthy cause here> should be asked to forgo movies, TV, music,
> all forms of entertainment.  Nor, for that matter, should they be allowed
> information or activity of any kind which is not conducive to the
> furtherance of <insert worthy cause here>.

Now flip that.  "People who say <insert worthy cause here> money would be
better spent on the space program should be asked to...."  Does that sound
reasonable to you?  No?  Didn't think so.

The whole point of NASA (originally) was to do things in space that the
private sector couldn't justify to The Consumer.  That has flipped 180
degrees, but the idea remains.  Give a democracy power of taxation and
power of budgeting, and it'll destroy itself quickly.

Essentially, if we want a space program, we'll have to buy stock in
private space companies (NOT milindustrial governmentplace contractors).
The uneducated, pap-fed population of this country simply isn't
interested in long-range planning beyond their new TV.


Elitist ranting from:
James Smith
[e-mail]

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

Date: 28 Aug 89 12:22:57 GMT
From: b.gp.cs.cmu.edu![e-mail]
Subject: Re: Voyager: Tape recorder?

In article <[e-mail]>, [e-mail] (Terry Hancock) wrote:
 >        This is what happens when it takes 10 or 20 years for a
 >spacecraft to get to its destination -- it's obsolete by the time
 >it arrives!

With current launch schedules, it's obsolete by the time it's launched.... :-(

--
UUCP: {ucbvax,harvard}!cs.cmu.edu!ralf -=-=-=-=- Voice: [phone] (school)
ARPA: [e-mail]  BIT: ralf%cs.cmu.edu@CMUCCVMA  FIDO: Ralf Brown 1:129/46
FAX: available on request                      Disclaimer? I claimed something?

"For numerical analysis, there are theorems that are true, and theorems that
 are *really* true."  -- John Dennis (in Upson's Familiar Quotations)

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

Date: 31 Aug 89 18:46:41 GMT
From: [e-mail]  (Jon Binkley)
Subject: Re: Galileo Jovian atmospheric probe -- is it sterilized???

In article <[e-mail]>
[e-mail] (Wayne Hayes) writes:
>I remember hearing a ruckus awhile ago regarding the sterilization of the
>the Galileo spacecraft's probe into Jupiter's atmosphere.  Aparently they
>were out of funds to sterilize it.  Is this still true?

As far as I know (not very), yes.

>In the remote
>possibility that Jupiter's atmosphere harbors indigenous life, we may
>pollute the atmosphere with Earth's life and never know for sure whether
>the life we later discover is in fact indigenous.

Actually we could tell with pretty high certainty whether or not life
we found there came from here; even in the unlikely event that the
putative alien used nucleic acids, those nucleic acids would stick out
like sore thumbs when compared at the sequence leval to terrestrial
DNA and RNA. (Unless, of course, both Earth and Jupiter were originally
seeded from the same group of extraterrestrials, using unsterilized
probes! :-)  If I was going to worry about anything (and I'm not),
I'd worry more about the terrestrial bacteria out-competing the natives.

>Thoughts?

I think that, while it would have been nice to sterilize the probe,
the importance of the mission far overshadows the minute chance of
inadvertantly colonizing Jupiter.

-Jon

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

Date: 31 Aug 89 22:39:15 GMT
From: skipper![e-mail]  (Mary Shafer)
Subject: Pegasus Status - 31 Aug 89

Just like the subject line says, it's time for a Pegasus status update.

The Pegasus is not attached directly to the B-52; rather, it's
attached to its own pylon which is attached to the B-52.  Using this
intermediate pylon means that the B-52 doesn't have to be modified for
each vehicle to be carried.  The Pegasus pylon was mated to the Dryden
B-52 late last week.

Early this week (Tuesday, I think) the Pegasus vehicle was mated to the
pylon.  I understand that this first mating went very well.

Today the B-52, with the Pegasus, went down to the Weight & Balance
Hangar, for weighing and center of gravity (cg) determination.

The latest word is that the project team is moving down the timeline
quite well and launch is still planned for October.

I'm not involved with this project, except as an interested bystander,
so this status mostly concerns progress visible as I walked by the
B-52.

I haven't followed the scheduling very closely--when was the first
launch originally scheduled?
--
--
Mary Shafer   [e-mail]  arpa!elxsi.dfrf.nasa.gov!shafer
         NASA Ames-Dryden Flight Research Facility, Edwards, CA
                    Of course I don't speak for NASA

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

Date: 31 Aug 89 20:52:51 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Re: Galileo Jovian atmospheric probe -- is it sterilized???

In article <[e-mail]> [e-mail] (Wayne Hayes) writes:
>I remember hearing a ruckus awhile ago regarding the sterilization of the
>the Galileo spacecraft's probe into Jupiter's atmosphere.  Aparently they
>were out of funds to sterilize it.  Is this still true?
>
>.. The fact that Jupiter
>may be too hostile for Earth bacteria to survive, or that there may be
>no life there, are simply risks I consider *much* too large.
>
>Thoughts?

I was under the impression that the general opinion is that life as we
know it could not survive on Jupiter, because downdrafts would carry
any life too deep into the atmosphere in a matter of days.  At high
temperature, the reaction of hydrogen with organic matter to form
methane, water and ammonia is rapid and exothermic.  Similarly, life
on Jupiter is thought to be unlikely, because complex prebiotic
molecules could not accumulate.

The technophobes might worry, but I'm not going to.

    Paul F. Dietz
    [e-mail]

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

Date: 29 Aug 89 16:25:16 GMT
From: ssc-vax!shuksan!tahoma![e-mail]  (James P. Galasyn)
Subject: Re: Message on Mars

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

> Uh, this proves that the *model* looks artificial as hell regardless of
> angles, and that the *model* is quite symmetrical.  It does not prove
> that this is the only model which fits the Viking photographs, or that
> the model corresponds to the Martian surface feature in question.

Quite so.  Keep me honest.

Jim "Death" Galasyn
..!uunet!bcstec!tahoma!jpg3196
..!uw-beaver!ssc-vax!shuksan!tahoma!jpg3196

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

Date: 1 Sep 89 01:41:09 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Re: Galileo Jovian atmospheric probe -- is it sterilized???

In article <[e-mail]> [e-mail] (Andy Stadler) writes:
>In article <[e-mail]> [e-mail] (Paul Dietz) writes:
>>
>> [..regarding sterilization of Galileo to protect Jovian life..]
>>
>>The technophobes might worry, but I'm not going to.

>Why must concern for life and environment == technophobe?  I program computers
>for a living, like to play with high-tech "toys", and support a strong
>program of space exploration; yet the thought of accidentally contaminating
>or even killing other yet unknown life forms scares and concerns me.

It's a question of perceived risk.  It is believed that the risk is very
small.  If one asks that the risk be zero, then one is a technophobe --
and, IMHO, a fool.

    Paul F. Dietz
    [e-mail]

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

Date: 1 Sep 89 05:07:20 GMT
From: ogccse!blake![e-mail]  (William Lewis)
Subject: Exotic Thrusters

In some article, [e-mail] (Paul Dietz) mentioned
MPDs, Magnetoplasmadynamic thrusters. (That's a mouthful...) I too
would like more information on these. I've heard that some have
been tested, and had quite high thrust &c., but a very short
lifespan: the components corroded or something. Sorry I don't have
any references on this. Might someone else (specifically, Paul
Dietz of `cs.rochester.edu'?)

    --- phelliax
        "I'm not a real message. I just play one on Usenet."

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

Date: 31 Aug 89 22:57:37 GMT
From: sco![e-mail]  (Stacey Campbell)
Subject: Re: Magnum snoopsat

In article <[e-mail]> [e-mail] (David Palmer) writes:
>    2) Geosynchronous orbit (presumably at the longitude of Moscow)
>    3) Sends data to the spy nest at Pine Gap, Australia.

A satellite in geosynchronous orbit over the European part of
the Soviet Union would be most unlikely to transmit to Pine Gap;
which would probably be the most remote station.

Are reconnaissance satellites ever placed in geosynchronous orbit?
--
Stacey Campbell - uunet!sco!staceyc - The Santa Cruz Operation

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

Date: 1 Sep 89 00:58:43 GMT
From: cs.utexas.edu!ut-emx!hutto![e-mail]  (Henry Melton)
Subject: Re: Mars "face" image data


That was fun, although I had to figure out how to put the data into a
MAC format.  Now that I have something to work with, it is interesting
to play with.  The raw data looks like junk .. but after you rotate it,
despeckle it, invert it, play with the contrast, and stare at it for a
while, it _does_ look like a face.

Now if I can only get the rest of the planet to play with ....


--
Henry Melton ...!cs.utexas.edu!ut-emx!hutto!henry
1-512-8463241 Rt.1 Box 274E Hutto,TX 78634

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

Date: Fri, 1 Sep 89 09:58:55 PDT
From: Peter Scott <[e-mail]>
Subject: Re: Neptune on the Boobtube

asuvax!mcdphx!mcdchg!ddsw1!corpane![e-mail]  (John Sparks)
writes:

>At one point a caller asked what will happen to Voyager, where will it go when
>it leaves the system.

>The answer was that in 8,000 years it will fly by Barnard's Star, in 20,000 or
>so it will pass Proxima Centauri, and then the Oort cloud.

I dunno about the Oort cloud, but the figures look right for Barnard's Star
and Proxima Centauri.  Remember that in these cases "closest approach" is still
several light years, and if you visualize the path, dropping perpendiculars
onto it from the stars... you get the picture.

Peter Scott ([e-mail])

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

Date: 1 Sep 89 15:01:03 GMT
From: cdp![e-mail]
Subject: Tracking Military Satellites


Tracking Military Satellites

I would be very interested in learning of anyone tracking low altitude American Military satellites - those for which the Godda
rd Satellite Situation Report lists "Current Elements Not Maintained." In particular, I am interested in obtaining orbital infor
mation on 1988-99A, launched from Vandenberg on 6 November 1988. I am also wondering whether there is a BBS for people who track
 such satellites, or which BBS's are likely to be a focus for such people.

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

End of SPACE Digest V10 #32
*******************