Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v09_3/v9_372.txt

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Subject: SPACE Digest V9 #372

SPACE Digest                                      Volume 9 : Issue 372

Today's Topics:
               Rail-Guns and Asteroids
             Re: Rail-Guns and Asteroids
       Acting NASA Administrator to resign (Forwarded)
              Re: long ago and far away
         Re: Soviet shutdown of manned space program
           Re: Soviet Mir space station in trouble
      Re: Thermal Pollution (was: Fusion: Expendible resources)
    thermal pollution (was: Fusion: Expendible resources)
          Re: UK astronaut to be launched by Soviets
         Re: U.S. vs Soviets (was Re: Alien contact)
             Venus radar mappers
----------------------------------------------------------------------

Date: Wed, 12 Apr 89 16:02 EST
From: [e-mail]
Subject: Rail-Guns and Asteroids

    Would it be reasonable to use Rail-Guns in mining an asteroid.
    I am thinking that a large pellet of metal could be fired from an
    asteroid based mining unit back to earth or the moon.  The pellet
    could either be tracked and caught when it gets near the earth,
    or it could be fired so it hits the moon, and then retrieved from
    the (new) lunar crater.  The shape and composition of a pellet would
    not be important.  Presumably, it should be small enough so that
    it could not survive reentry on earth.  (Decreases liability
    insurance.)  The rail gun could be operated with fusion or solar
    generated electricity.

    The advantage of this scheme is that a mining operation could return
    a continuous supply of raw materials, without requiring complex
    rockets to return it.  The only rockets/chemical fuel needed would
    be to transport the mining equipment and miners to the site, and
    return the miners.

    Could this scheme be used in reverse?  Could water, food, fuel and
    other supplies be sent to mars or an asteroid mining site using
    rail guns?

    Chris Eliot
    Umass Amherst

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

Date: 14 Apr 89 03:15:39 GMT
From: blake![e-mail]  (William Lewis)
Subject: Re: Rail-Guns and Asteroids

In article <[e-mail]> [e-mail] writes:
>    Would it be reasonable to use Rail-Guns in mining an asteroid.
>    I am thinking that a large pellet of metal could be fired from an
>    asteroid based mining unit back to earth or the moon. ...

   The problem is that any pellet massive enough to send to Earth (or the moon
or...) would be massive enough to make the railgun recoil quite a bit. Either
you can make the railgun very massive (by using the unused bits of asteroid
as a momentum sink), or try to make the recoil push the railgun in a useful
direction (such as the next asteroid down the line.) The problem with the latter
is that Earth would probably not always be the best direction to throw
something to get said something to the asteroid belt.
>                                                     ...   The pellet
>    could either be tracked and caught when it gets near the earth,
>    or it could be fired so it hits the moon, and then retrieved from
>    the (new) lunar crater. ...

Of course, you'd lose quite a bit of material blasted away by the impact.
Very impracticl / inefficient.
>                    .... The shape and composition of a pellet would
>    not be important. ...
  Huh? The composition not important? Why do you go to all this trouble
to fire garbage pellets at Earth? I'd at least want the pellets to be
something I can use!
>          ....  Presumably, it should be small enough so that
>    it could not survive reentry on earth.  (Decreases liability
>    insurance.)
    [stuff about reuseability & electrical-powered-ness of railguns]
   Why railguns? Why not magnetic linear accelerators? Or giant electrically
powered catapults (the miners can grow their hair long, you see, and...)?

>    rockets to return it.  The only rockets/chemical fuel needed would
>    be to transport the mining equipment and miners to the site, and
>    return the miners.

  Why use miners at all? Strikes me this could be more easily automated...
which makes the whole package cheaper, lighter, etc.

~~~~~~~~.sigs in spaaaaaace!~~~~~~~~~

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

Date: 12 Apr 89 23:14:25 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Acting NASA Administrator to resign (Forwarded)

David W. Garrett
Headquarters, Washington, D.C.


RELEASE:  89-49

ACTING NASA ADMINISTRATOR TO RESIGN


     Dale D. Myers, the acting NASA administrator, has announced
his plans to resign effective May 13, 1989.

     Myers, acting administrator since April 8, 1989, served as
the NASA deputy administrator from Oct. 6, 1986, when he was
called back to NASA by President Reagan.  During this tenure,
Myers was instrumental in guiding NASA through the period of
recovery following the Challenger accident of Jan. 28, 1986.

     Some major accomplishments during this period were the
substantial redesign of the Space Shuttle system including the
solid rocket motor and the subsequent return to manned space
flight in September 1988; reorganizing the Space Shuttle
management structure and centralizing the Space Station
management; and the reinstitution of a mixed fleet strategy using
commercial expendable launch vehicles in addition to the Shuttle.

     In his letter of resignation to President Bush, Myers wrote,
"I am most grateful for the opportunity to be of service to the
Nation.  I will continue to support you and this administration
to the best of my ability in the years to come."

     Myers has served two tours at NASA Headquarters -- his
present position and earlier as the associate administrator for
manned space flight from 1970 to 1974.  He also served as under
secretary, U.S. Department of Energy from 1977 to 1979.  From
1974 to 1977, he was vice-president, Rockwell International, and
president, North American Aircraft, El Segundo, Calif.

     Born on Jan. 8, 1922 in Kansas City, Mo., Myers is a
graduate of the University of Washington, Seattle, with a B.S. in
aeronautical engineering.  He received an honorary doctorate from
Whitworth College, Spokane, Wash., and distinguished service
medals from both NASA and the Energy Department.  He was elected
to the National Academy of Engineering in 1974.

     Myers is married to the former Marjorie Williams of Seattle
and they are the parents of two daughters.

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

Date: 13 Apr 89 19:25:22 GMT
From: att!homxb!homxc![e-mail]  (B.REYTBLAT)
Subject: Re: long ago and far away



Not so long ago, nor as far away:

On april 12, 1981, STS-1 lifted off from pad 39-(A or B, Henry?).

Ben Reytblat
no cute signature
no cute disclaimer

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

Date: 14 Apr 89 04:57:20 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Soviet shutdown of manned space program

In article <Added.gYF=[e-mail]> [e-mail] writes:
>  I just heard that the CCCP is not putting up manned missions for a while
>(anyone heard how long?).   Maybe all the discussion of how much the sov
>governments subsidises things is true.  Could be there is a big shakedown in
>their equivalent of OMB...

Or could be they simply have technical problems on Mir and this is a
temporary exigency.  Frankly, folks, the only *fact* we have right now
is that there will be an interruption in the continuous manning of Mir.
I don't think I've ever seen such elaborate pyramids of speculation
built on such slender evidence.  To make anything deep and significant
out of this, you basically need to assume that the Soviet space program
is run in the same chuckleheaded what-shall-we-do-in-space-today fashion
as the US space program (and indeed, most programs of any kind that are
funded on a year-to-year basis by democratic governments).  That's what
it takes to justify an abrupt shutdown of a major ongoing program.
To date, there is no sign whatever of the Soviets employing this
particular form of mismanagement.  (They have their own forms, heaven
knows, but this isn't one of them.)  It would be very suprising to see
such a radical change now.

It's enough to make one suspect that some of the speculators have private
axes to grind.
--
Welcome to Mars!  Your         |     Henry Spencer at U of Toronto Zoology
passport and visa, comrade?    | uunet!attcan!utzoo!henry [e-mail]

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

Date: 13 Apr 89 16:53:08 GMT
From: visdc![e-mail]  (John E Van Deusen III)
Subject: Re: Soviet Mir space station in trouble


I have read speculation that after the failures of Phobos I and II and
in consideration of the minimal gains that can be derived from beating
the US in a race in which it declines to participate, the Soviets
decided that the money spent upon an aggressive manned space program
could better be spent on earth.  They are simply cutting back.
--
John E Van Deusen III, PO Box 9283, Boise, ID  83707, [phone]

uunet!visdc!jiii

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

Date: 13 Apr 89 21:40:20 GMT
From: haven!aplcen!aplcomm!stda.jhuapl.edu![e-mail]  (Jim Meritt)
Subject: Re: Thermal Pollution (was: Fusion: Expendible resources)

In article <33@boston-harbor> [e-mail] writes:
}In article <[e-mail]> [e-mail] (Byron Rakitzis) writes:
}>
}>I think there's a far more important long-term concern which we must
}>bring to our attention: thermal pollution. Whereas solar, wind etc.
}>power essentialy harness the energy in the environment, fusion would
}>place all this "extra" energy previously stored in deuterium nuclei
}>into the environment. I would not be surprised if we found ourselves,
}>in the long term, having to limit the use of such non-reversible
}>processes as deuterium-fusion.
}
}If you are talking about thermal pollution of the earth as a whole
}it's not likely to become a big problem unless we become incredibly
}profligate with energy usage.  There are many orders of magnitude
}between the amount of energy the earth receives from the sun and the
}amount that human beings use currently.  We can increase our energy
}usage quite a bit before heating the earth will be a problem.

If we start throwing so much energy around that the waste starts cooking
us we'll also have enough on hand to move the planet away from that
nastey old unpredictable star heating up the works.

Puppetteers: mind sending the specs via Niven?
;-)


Disclaimer:  "It's mine!  All mine!!!"
                    - D. Duck

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

Date: 14 Apr 89 11:58:48 GMT
From: spdcc![e-mail]  (Steve Elias)
Subject: thermal pollution (was: Fusion: Expendible resources)

In article <[e-mail]> [e-mail] (Jim Meritt) writes:
!In article <33@boston-harbor! [e-mail] writes:
!} [e-mail] (Byron Rakitzis) writes:
!}!
!}!I think there's a far more important long-term concern which we must
!}!bring to our attention: thermal pollution. Whereas solar, wind etc.
!}!power essentialy harness the energy in the environment, fusion would
!}!place all this "extra" energy previously stored in deuterium nuclei

    fusion isn't the only power source that could add to our
    thermal problems.  how about nuclear fission?  solar satellites?

!}If you are talking about thermal pollution of the earth as a whole
!}it's not likely to become a big problem unless we become incredibly
!}profligate with energy usage.  There are many orders of magnitude
!}between the amount of energy the earth receives from the sun and the
!}amount that human beings use currently.  We can increase our energy
!}usage quite a bit before heating the earth will be a problem.

    we've got about a factor of 100 or 1000 to go before we reach
    the same power level as that received via solar flux...
    but our energy usage is growing by 7% a year or so.  it won't
    take too long to reach that factor of 100.  (these numbers
    have been bandied about sci.physics/misc for the last year or so.)

!If we start throwing so much energy around that the waste starts cooking
!us we'll also have enough on hand to move the planet away from that
!nastey old unpredictable star heating up the works.

    what you really mean is that we'll be off planet by then,
    spending our heat/energy where it won't toast the earth's
    environment...  right?  there are surely more direct thermal
    dangers than 'waste heat', today.  but we shouldn't ignore
    potential or current environmental problems just because we'll
    be able to 'escape to space' some day...
--
   Steve Elias ([e-mail]);(6172399406)
     "Space is small.  The planets are big." -- Heinlein

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

Date: 14 Apr 89 07:46:48 GMT
From: mcvax!hp4nl!esatst![e-mail]  (Neil Dixon)
Subject: Re: UK astronaut to be launched by Soviets

In article <[e-mail]> [e-mail] (Clive) writes:
>According to BBC Ceefax news this morning (Thursday), the UK's first
>astronaut will be launched by the Soviets in 1991.

1991, Thatcher's next election year. A cheap publicity stunt is
obviously more important than any participation in Europe's own
(albeit flawed) manned space program. It will be interesting to see
how this can be justified, since their is no obvious profit to be
made; but then again, there's always the T-Shirts, Commemorative Book,
Record, Video, etc :-).

Disclaimer: I'm sure nobody in ESA agrees with me.
--
Neil Dixon <[e-mail]> UUCP:...!mcvax!esatst!neil, BITNET: NDIXON@ESTEC
Thermal Control & Life Support Division (YC)
European Space Research and Technology Centre (ESTEC),
Noordwijk, The Netherlands.

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

Date: 14 Apr 89 14:55:56 GMT
From: prism![e-mail]  (Matthew DeLuca)
Subject: Re: U.S. vs Soviets (was Re: Alien contact)

In article <[e-mail]>, [e-mail] (Henry Spencer) writes:
> In article <[e-mail]> [e-mail] (Matthew T. DeLuca) writes:
> >What wondrous capabilities is New Mir expected to have that Freedom won't?
>
> Turn it around:  what wondrous capabilities is Freedom expected to have
> that Mir doesn't?  Yes, it will be bigger... but Skylab was bigger yet
> (yes, last I heard Freedom's internal volume will be less than that of
> Skylab)...
An article on the space station was in the May 1989 issue of Discover that
came out yesterday.  Showed the latest design for the station: two 40-foot
U.S. modules (1 hab, 1 lab), 1 40-foot ESA module (lab), and 1 20-foot
Japanese module (lab).  Also included is a 20-foot free-flying ESA module
for long-term, sensitive experiments.  Solar arrays provide 224,000 watts of
power.  This seems to be a bit more voluminous than a gutted Saturn V third
stage, and the power supply will allow us to run fairly energy-intensive
projects.  Incidentally, you avoided my question: you were going on about
the probable superiority of Novy Mir...again, what greater capabilities will
it have?

> >> [past glories of US planetary missions]
> >... What do the Soviets have in the pipeline in this class?
>
> What does the US have in the pipeline in this class?  Mars Observer is
> deliberately a rather unambitious mission.  Cassini and friends can't
> really be said to be in the pipeline yet -- they've been trying to get
> in for years.

I wouldn't call Mars Ovserver unambitious.  From the looks of it, it is a
fairly sophisticated mission that will multiply our knowledge of Mars
manyfold.  We're beyond the days of the numerous, cheap probes whose sole
mission was to survive long enough to snap pictures.  We have pictures; now
the mission is a lot more complex, and you can't have five or ten of them
in the planning stage; it's just too expensive.  Last I heard, Cassini was
entering the pipeline; there was something in an AvWeek article about funding,
although I don't remember what issue.  It's going to be a while before Cassini
goes anywhere, but then again, Saturn's not leaving the system anytime soon,
either.

--
--------------------------------------------------------------------------------Matthew DeLuca                      :
Georgia Institute of Technology     : Certainty is the lot of those who
ARPA: [e-mail]      :           do not question.
--------------------------------------------------------------------------------

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

Date: Fri, 14 Apr 89 14:52:32 EDT
From: John Roberts <[e-mail]>
Formerly: National Bureau of Standards
Sub-Organization: National Computer and Telecommunications Laboratory
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Venus radar mappers


>From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
>Subject: Re: alien contact

>In article <[e-mail]> [e-mail] (Matthew T. DeLuca) writes:
>>... Assuming nothing goes wrong (fingers crossed), we'll be sending
>>new probes out to Venus, to get the highest quality maps of that planet ever,

>Do remember that the highest-resolution maps of Venus existing right now
>came from Soviet missions.  This is another catchup mission.

My understanding of the situation is that the best existing radar map of
*most* of the planet was produced by a US probe. Soviet probes then provided
a higher resolution map, but only of a small fraction of the surface, around
25%. Now another US probe is supposed to produce a map with still higher
resolution, and again of nearly all the surface. It seems to me that this is
not a matter of "catching up", but of two separate programs with different
agendas, which have been working with one another in a cooperative manner.

It often appears that there is a tacit understanding between the planetary
science programs of the US and the USSR which tends to limit duplication
of effort. There is also sometimes direct cooperation, as in the case of
the Phobos probes and of several Venus probes. This cooperation has continued
even at times when the official relations between the two countries were
very poor.
                                 John Roberts
                                 [e-mail]

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

End of SPACE Digest V9 #372
*******************