Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v13_2/v13_225.txt

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Subject: SPACE Digest V13 #225

SPACE Digest                                     Volume 13 : Issue 225

Today's Topics:
               Re: Lunar oxygen
              Galileo Update - 03/01/91
         external tank use, practical issues thereof
              WWN does it again!
         Re: Terraforming, ethics of human existance.
                   I-CON X

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Date: Fri, 1 Mar 91 19:24:35 EST
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
To: polari![e-mail], [e-mail]
Subject: Re: Lunar oxygen



>Date: 1 Mar 91 01:28:00 GMT
>From: hub.ucsb.edu!ucsbuxa![e-mail]  (Charles Frank Radley)
>Subject: Re: Space Profits

>The advantages of lunar oxygen (Lunox):-

>Delta-vee to LEO from Luna is much less than from Earth to LE O

>Hence getting LOX to LEO is cheaper if it originates from the
>Moon.

To be fair,
 - LOX will cost much more per pound on the surface of the moon than on the
   surface of the earth.
 - Delta-V will initially cost much more per kg * m/s from the moon than
   from earth. It may eventually cost much less, if a linear launcher is
   built on the moon. (On the other hand, the same might be done on Earth.)

So there's a tradeoff, with an accurate cost comparison requiring careful
analysis. I think it's worth looking into.

>LOX is a very valuable commodity to have in LEO because it can be
>used to boost satellites from LEO to high orbit, eg
>communications satellites.  It can also be used to prevent
>spacecraft in LEO  (eg Space Stations) from decaying.

>GEO comprises Oxidizer.   Cheap Lunox would thus dramatically
>reduce the cost of launching spacecraft into GEO.

Please elaborate.

     John Roberts
     [e-mail]

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

Date: 2 Mar 91 01:06:03 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Galileo Update - 03/01/91


                          GALILEO STATUS REPORT
                             March 1, 1991

     The status of the Galileo spacecraft as of end of the day of February 28
is as follows:

        o System Power Margin - 64 watts
        o Spin Configuration - Dual-Spin - cruise mode
        o Spin Rate/Sensor - 3.15 rpm
        o Spacecraft Attitude Sun Point Angle - approximately
          3.7 degrees (lagging) plus or minus 0.3 degree
        o Downlink telemetry rate/antenna - 40 bits/second
          (uncoded)/LGA-1 (Low Gain Antenna-1)
        o General Thermal Control - all temperatures within
          acceptable range
        o RPM Tank Pressures - all within acceptable range
        o Probe - powered off, temperatures nominal
        o Command Loss Timer Setting - 240 hours
          Time To Initiation - 216 hours

     Today, the spacecraft activities will consist of:

        o Powering on the EPD (Energetic Particles Dectector)
          instrument for its periodic motor maintenance activity.

        o Performing a SITURN activity to lead the sun.

        o Performing an EUV (Extreme Ultraviolet Spectrometer)
          memory readout.

     No spacecraft activities are planned over the weekend.

     A total of 3239 real-time commands have been transmitted to Galileo.  Of
these, 1803 have been pre-planned in the sequence design and 1436 were not.
In the past week, a total of 19 real-time commands were sent; one was
pre-planned.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [e-mail]
     | | | |  __ \ /| | | |      Jet Propulsion Lab | Is it mind over matter,
  ___| | | | |__) |/  | | |___   M/S 301-355        | or matter over mind?
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 | Never mind.
 |_____|/  |_|/       |_____|/                      | It doesn't matter.

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

Date: 1 Mar 91 22:18:52 GMT
From: ucivax!jarthur!elroy.jpl.nasa.gov!sdd.hp.com!cs.utexas.edu!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: external tank use, practical issues thereof

In article <[e-mail]> [e-mail] (Charles Frank Radley) writes:
>+... Anywhere you can
>+bolt a hatch you can bolt an  airlock instead, without any
>+fundamental difficulties.
>-
>   ?? Really.... Would not hold pressure very long !   Airlocks
>involve complex redundant labyrinth seals.    A bolted interface
>is no good.

References, please.  I would be somewhat surprised to see labyrinth seals
used in airlocks at all, because they do *not* stop leakage, they only
slow it down -- they are normally used only in cases like rotating shafts
where a bolted/latched interface seating on a gasket is impractical.

My references don't specify what the shuttle airlock uses, but the side
hatch uses latches and a gasket, and the same was true of the Apollo
hatches.  The Apollo docking interface used latches and gaskets.
For that matter, bolts and gaskets are the normal sealing technology
ground-based in vacuum, high-vacuum, and ultrahigh-vacuum systems.
Bolted interfaces work just fine.

If you want still another example, the Gamma-Ray Imaging Telescope project
plans to use the (bolted, gasketed) seals on the external-tank access
hatches to hold gas pressure inside for years, with no resupply flights
and only a limited make-up supply on board.

>+ As I may have mentioned before, the people working on the
>+Gamma-Ray Imaging  Telescope concept have already sorted out
>+the details of opening one of  the hydrogen-tank manholes and
>+getting both men and equipment in through it.  No major problems...
>-
>  Interesting.  Please tell us how they plan to install an
>airlock.   Windows would be nice too.  Which of them volunteered
>to be the first one to go through the airlock without a suit on ?

None of them.  You didn't read what I wrote.  They're not putting in
an airlock at all.  However, they *are* moving both men (in spacesuits)
and equipment into the interior during construction work.  They think
the access manholes are entirely adequate for the job.

>+ Unbolt a manhole, slide in an airlock with a mounting flange
>+matching the  outer rim of the manhole cover, and bolt it
>+ down.  Bingo.
>-
>    Sorry, you just failed the leak test.   Start again.

I'd be very curious to hear the details of this "leak test", and how an
Apollo spacecraft docked to Skylab passed it.  (Yes, the connecting tunnel
was normally pressurized, and open to Skylab in fact.)

>  Nobody has ever installed a kluge fit airlock in orbit, not
>even the Soviets want to be the first to take that risk.

Both the US and Soviets have docked spacecraft to each other in orbit
numerous times, with pressurized tunnels connecting them.  Where is the
problem with docking an airlock instead?  If anything, we can do a better
job on the airlock joint, since it will not have to undock again and
it can be firmly bolted in place with a plastic-deformation gasket.
(This is what is normally done in ultrahigh-vacuum systems:  the gasket
is a one-use type that is, literally, crushed between joint surfaces.)

>+There is a 46x52-inch access door in the side of the intertank
>+structure... Please be specific about *why* +breaching this
>area is a no-no.
>+
>   There is nothing wrong with breaching the intertank area from
>the outside.  What I meant was breaching the barrier between the
>two tanks, explosive mix and all that.  This means that there is
>no communication or acess possible from one tank to the other.
>As well as an airlock to the outside, holes must be cut in the
>two tanks then they will need a hermetically sealed tunnel to
>connect them...

Please go back and re-read my previous posting.  There are *already*
access hatches from both tanks into the intertank area; that is the
only access hatch in the oxygen tank, in fact.  No cutting will be
needed.  It ought to be possible to pre-install the tunnel, although
it may add some small complexity to the system that maintains an
inert atmosphere in the intertank area.  (Yes, there is such a system,
although I'm not sure of the details.)  After the tanks have been
vented to space, there will be no possibility of an explosive mixture
and hence no problem in opening up the tunnel hatches, although this
would probably have to be done by going in through the side door and
opening a side hatch on the tunnel, since the hydrogen-tank hatch is
undoubtedly not designed to be opened from inside!
--
"But this *is* the simplified version   | Henry Spencer @ U of Toronto Zoology
for the general public."     -S. Harris |  [e-mail]  utzoo!henry

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

Date: 3 Mar 91 18:39:15 GMT
From: uokmax![e-mail]  (Jonathan A Bishop)
Subject: WWN does it again!


     Yes, folks, the Weekly World News, the people who brought you the hidden
Challenger transcripts, have done it again!  They have conclusively
that the moon landing was a hoax, and they have sidebars to prove it!
     Their evidence comes from Bill Kaysing (the name sounds familiar... who is
he, and did he ever really work at Rocketdyne?), who offers the following
incontrovertible proof:

1)  NASA has never released any photos in which the moon can be seen in
relationship to planets other than Earth, because those relationships would
be almost impossible to fake.  Also, he says that the Earth in pictures from
the Moon is too small.  (I don't know, Kepler's laws don't seem too difficult
to me...)

2)  He says the LEM didn't kick up any dust, but that the astronauts' boots
sink into the soil, and that the boots sink in more than the LEM footpads.
(I'll have to analyze my tapes more; I always thought Buzz said "Picking up
some dust" just before the alleged touchdown, but I must be mistaken...)

3)  The information about the moon missions is not classified, but information
is not available to the public.  (So, I must have been hallucinating when I
thought I was reading all the technical reports about the missions...)

4)  The Apollo astronauts have stated that they don't want to discuss the
missions.  (True, Neil is happy to stay on his farm, and you don't see much
of Buzz, but Mike Collins seems to me to be the kind of guy who'd be happy to
talk about it all day.  Not to mention Pete Conrad, Gene Cernan, Frank Borman,
Alan Shepard, and John Young, all of whom seem talkative; then there's Tom
Stafford, who I've talked to for several hours...)

5)  The space suits the astronauts wore were not designed for the
temperature extremes of the Moon.  (So Rocketdyne built the suits too?)

6)  The Van Allen belts should have "burned them to crisps."  He points out
that astronauts who merely orbit the Earth don't encounter them.  (Wait...
that means that some of the Gemini flights must have been faked too!  This
deserves further investigation!)

Finally, my favorite:
7)  There is a picture showing astronauts training on one of the lunar surface
mock-ups, with a caption pointing out that girders can be seen in the picture.
(The technical people really dropped the ball on this one, since they also
forgot to put the gold foil on the LEM, and one of the astronauts has his sun
visor up.)

A couple other points are brought up, but these should be enough to convince
anyone (under the age of six, anyway).

I guess I need to modify my .sig...
--------
[e-mail]

"I'm with you, LEM, though it's a shame that it had to be fake.
 The mother ship is just a set in which to do a take.
 I'm with you, boys, oh, there's something I just thought of.
 It's on my mind, we should be on the Moon, but we're in Nevada."
            --(Not Quite) Jethro Tull, "For Michael Collins, Jeffrey, and Me"

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

Date: 2 Mar 91 19:45:01 GMT
From: crash!orbit!pnet51![e-mail]  (S Schaper)
Subject: Re: Terraforming, ethics of human existance.


 Heidi,
   It sounds like you have a serious death wish. Get help.
**************************************************************************
Zeitgeist Busters!
UUCP: {crash tcnet}!orbit!pnet51!schaper
INET: [e-mail]
           Aslan is on the move!
****************************************************************************

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

Date: 3 Mar 91 18:03:20 GMT
From: att!cbnewsi![e-mail]  (The Resource, Poet-Magician of Quality)
Subject: I-CON X




           I  -  C  O  N     X

   The East Coast's Largest Convention of
        Science Fact,
            Fiction,
                and Fantasy

             April 19-21, 1991
State University, Stony Brook, Long Island, NY




Science Guest-of-Honor: Robert L. Forward


        Science and Technology Special Guest: Deke Slayton
        Mercury and Apollo Astronaut


[Negotiating with a Russian cosmonaut as well.]
[Full Science Track guest list available on request.]


SciFi Track:
Special Guest: Harlan Ellison
        Guest-of-Honor: Dan Simmons
        Author of the Hugo Award winning novel Hyperion
[Full SciFi, Fantasy, Horror, Art, Comics, Trek, and Who guest
lists available on request.]

       In addition to the personal appearances, panels and film
       program, I-CON features an Art Show, Meet the Pros Parties,
       dealers' rooms, writers' workshops, autograph party, no-
       minimum-bid auctions, gaming, filksinging, japanimation,
       model rocketry, gaming tournaments, sneak previews of
       upcoming films, videos, stargazing, ...

Ticket Information:

       $20 until March 31, 1991 (Children 5-11 years old, $8).
       $25 at the door (Children 5-11 years old, $10).
       Children under 12 must be accompanied by a ticketholding
       adult at all times.

  I-CON
  P.O. Box 550
  Stony Brook, NY  11790

       For more information, send email to [e-mail].
       Please do not call...but if you call, at least leave a phone
       number so I can get back to you.
--
Brian Charles Kohn          AT&T Bell Laboratories Quality Process Center
Quality Management System   E-MAIL: att!hoqax!bicker  ([e-mail])
Consultant                  PHONE: [phone]        FAX: [phone]

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

End of SPACE Digest V13 #225
*******************