Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v09_5/v9_572.txt

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Subject: SPACE Digest V9 #572

SPACE Digest                                      Volume 9 : Issue 572

Today's Topics:
    Re: Space Quest, Re: space news from June 19 AW&ST...
         Re: Magellan Status for 07/17/89 (Forwarded)
             Voice channel beeps.
    Does this proprosal make sense ? (was RE: SPACE QUEST)
      Re: Does this proprosal make sense ? (was RE: SPACE QUEST)
                 Re: Modules
            George Koopman killed
            The Soviet ZOND lunar probes.
              Re: S-Band Beacon on Moon
             "The other side of the Moon"
               Re: latest Quayle gaffe
         Re: Magellan Status for 07/17/89 (Forwarded)
----------------------------------------------------------------------

Date: 21 Jul 89 14:00:42 GMT
From: watmath![e-mail]  (Fred Walter)
Subject: Re: Space Quest, Re: space news from June 19 AW&ST...

In article <[e-mail]> [e-mail] (Daniel Pezely) writes:
>Well, space is important to me and many people I know.  This fall I was
>planning on organizing everyone that I could possibly find and form The
>Space Quest Foundation.
>
>I would like to approach all of the space contractors with a proposal.
>Most companies are formed as profit making institutions.  With that in
>mind, why don't we form an alternative space administration which is
>OWNED by the space contractors?

I don't see what benefit the space contractors would get out of it. They'd
be giving up something (whatever they gave you); in return they'd get more
people telling them what to do - people who don't have any money to pay
for putting payloads in space.

>There's a lot that needs to be done.  Anyone interested?  Here's a chance
>to actually do something.  If you don't try, then you wont succeed.  Send
>me mail if you're interested and determined to do something.

I'm interested in doing something, but I don't see the above ever happening.
No company interested in turning a profit will give up something just to get
more administration. If I've misinterpreted something, please let me know.

However, the above does give me some ideas...

    fred

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

Date: 21 Jul 89 14:27:37 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: Magellan Status for 07/17/89 (Forwarded)

In article <[e-mail]> [e-mail] (Peter G. Ford) writes:
>But what, you ask, is a "momentum wheel desaturation?" Well, the wheels
>are much less massive than the rest of the spacecraft (technically,
>their moments of inertia are much smaller), so they must spin up to
>very high rates to turn Magellan in a reasonable time. To avoid their
>spinning so fast that they fly apart, there are auxiliary rockets on
>Magellan that are fired from time to time to give the spacecraft a
>strong twist in the opposite direction, thereby allowing the wheels to
                     ^^^^^^^^
>be spun down and "desaturated".

Jeez I hate to disagree with someone on the Project, but wouldn't the
thruster burns be twisting the spacecraft in the SAME direction as the
momentum wheels' accumulated spin, rather than in the OPPOSITE
direction?  If you add more opposite torque you'd have to spin the
wheels even faster to compensate.  By tweaking in the same direction,
you allow[require] spindown of the wheels to compensate.

That's what I said in my mailed explanation anyway.  If it's wrong I'd
like to know it.
--
"My God, Thiokol, when do you     \\    Tom Neff
want me to launch -- next April?"  \\    uunet!bfmny0!tneff

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

Date: 21 Jul 89 17:10:25 GMT
From: voder!berlioz![e-mail]  (Bill Bencze)
Subject: Voice channel beeps.


This is a question that always has been bugging me and I have never
been given a good answer:

What function do the ever present "beeps" serve in the voice
communication between spacecraft and the ground? These are the
1~3 kHz beeps of about a half second in duration which seem to
occur at random duning the transmissions.  Are they electronic
"Over" signals automatically sent at the end of a transmission or
some other type of timing signal.

Please satisfy my curiosity!!!


Bill Bencze.
National Semiconductor Corp.

[e-mail].

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

Date: 21 Jul 89 18:40:52 GMT
From: watmath![e-mail]  (Fred Walter)
Subject: Does this proprosal make sense ? (was RE: SPACE QUEST)

The article about forming a group (Space Quest) got me thinking.

Why not form a non-profit organization whose goal is to get everyone of its
members off the planet ?

The work would be done by the members; all money raised would be put back
into the organization to better the facilities/do R&D/etc.

The administration of the group would serve to connect people together
into working groups. They would gather information on the members
(regarding what everyone can do/will do) and give the information to its
members and ask the members for possible plans of action. The
administration would then gather all the plans and try and condense them
into one plan, which would be given back to the members. This would bounce
back and forth until a plan was had that everyone could live with.

I can describe this better by giving a possible scenario :

    You have engineers who are willing to design a rocket
    that would be able to put a payload into orbit. You have
    machinists who are willing to produce the parts (and
    who are willing to produce the equipment needed to
    produce the parts). You have salemen/marketers who are
    willing to try and find people/corporations/etc who have a
    satellite that they will pay to have put in orbit. Plus
    you have people who are willing to do all the other necessary
    things.

    The administration would design a plan based on plans submitted
    by the members (eg. engineer 1 designs this part; engineer 2
    designs this part; etc.) and gives it back to the members.
    The members would give critique the plan (engineer 1 says that
    he doesn't have the time to do part A, but he can do part T;
    engineer 3 says he can do more then he's been given; engineer 7
    has some fancy hardware/software that will make certain jobs
    easier and is willing to let other people use it; etc. etc).

    Eventually, a rocket would be build, a satellite launched, and
    non-member money would come in, which would be used to improve
    facilities, so that bigger/better rockets could be built.

    Etc. Etc.

In return for giving time/money to the organization, one would get some
number of shares. When the stage is reached that people are actually being
sent into space, then the people with the most shares are the people who go
first.

Once the organization is in a position where money is coming in, it could,
instead of shares, remunerate with money the people who give time (IE. said
machinist/whatever could be able to live while working on projects and
gaining shares).

This is a pretty rough outline. Does anyone see any obvious flaws ? Does
anyone have any suggestions ? Is anyone willing to help organize something
like this ?

    fred

[e-mail]                  (Canadian domain)
[e-mail]                  (US Internet, including CSNET)
[e-mail]                  (CDNnet and some European nets)
watmath!grwalter                               (UUCP)
uunet!watmath!grwalter                         (another UUCP alternative)
[e-mail] (ARPA)

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

Date: 21 Jul 89 19:21:15 GMT
From: [e-mail]  (Jonathan Patrick Leech)
Subject: Re: Does this proprosal make sense ? (was RE: SPACE QUEST)

In article <[e-mail]> [e-mail] (Fred Walter) writes:
>Why not form a non-profit organization whose goal is to get everyone of its
>members off the planet ?

    This used to be called the L-5 Society, before it was sucked into
the near-term political morass...  I'm fond of Keith Lofstrom's
suggestion that we start an L-4 Society.

    The largest existing organization which comes close to what you
mention is the Space Studies Institute.  Become a member, give
everything you can, and SSI may be able to develop the tools to get
us off the planet (my standard offer of details about SSI by email
request goes here).
--
    Jon Leech ([e-mail])
    Apple Integrated Systems
    __@/

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

Date: 20 Jul 89 17:18:07 GMT
From: [e-mail]  (Bill Chiarchiaro)
Subject: Re: Modules

In article <[e-mail]>, [e-mail] (Doug Krause) writes:
>
> I lost a couple of articles.  Was Snoopy an LM or CM?  If it was
> an LM, a historic quote would have a whole new feel.


Snoopy was the name for the Apollo 10 LM.  The Apollo 10 CSM was
called Charlie Brown.

Bill Chiarchiaro
N1CPK
[e-mail]

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

Date: 21 Jul 89 20:36:39 GMT
From: [e-mail]  (Bill Ganoe)
Subject: George Koopman killed

New York Times, Friday, July 21, 1989 (page A11) carried the obituary
for George Koopman, founder of the American Rocket Company (AMROC).
He was killed when his car overturned on the way to the Air Force
Astronautics Laboratory at Edwards AFB, California.

George was a man with a vision and the capacity to overcome
towering obstacles in the way of space commercialization.
He will be sadly missed -- especially by those of us who knew him..

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

Date: 21 Jul 89 20:37:00 GMT
From: wrksys.dec.com![e-mail]  (CUP/ASG, MLO5-2/G1 6A, 223-3283)
Subject: The Soviet ZOND lunar probes.


        Someone recently mentioned about several unmanned Soviet ZOND
    probes actually landing on Earth's Moon.  This is incorrect:  Of
    the ZOND probes sent on lunar missions between 1965 and 1970
    (ZOND 3-8), none of them landed on the lunar surface, though most
    of them did orbit the Moon.  It is generally believed that these
    ZOND probes were tests for a manned SOYUZ mission to orbit and/or
    land on the Moon.  Such plans did not come to pass.

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

             N = R*fgfpneflfifaL

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

Date: 22 Jul 89 00:53:53 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: S-Band Beacon on Moon

In article <[e-mail]> [e-mail] (Joe Dellinger) writes:
>Here's a question I've always wanted to ask: why even bother to shut the
>things off? Just ignore them, and if they're still working a few years later
>when you change your mind, so much the better.

Unfortunately, spectrum space is not in overwhelmingly abundant supply, so
it's considered desirable to shut down transmitters that you are no longer
listening to.  (It is also considered desirable to have a way to shut the
transmitters absolutely and permanently off, so they can't reawaken due to
static in the receivers and the like.)

>If they had shut off the
>deep space network, would they have given a command to the Voyagers and
>pioneers "make no further broadcasts, accept no further instructions from
>Earth"?

Very probably.
--
1961-1969: 8 years of Apollo.  |     Henry Spencer at U of Toronto Zoology
1969-1989: 20 years of nothing.| uunet!attcan!utzoo!henry [e-mail]

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

Date: 20 Jul 89 09:05:16 GMT
From: shelby!portia!hanauma.stanford.edu![e-mail]  (Joe Dellinger)
Subject: "The other side of the Moon"


    A different sort of Apollo TV show is PBS's "The other side of
the Moon". They cover what several of the Apollo astronauts are doing TODAY.
It was pretty surprising:

    One is a test pilot...
    One sells coors beer in Mississippi...
    One paints moonscapes...
    One flies around Mt Ararat (Turkey) looking for Noah's ark...
    One believes humans are descendants of an alien space-faring race...


    All in all, a typical group of average Americans!
\    /\    /\    /\/\/\/\/\/\/\.-.-.-.-.......___________
 \  /  \  /  \  /Dept of Geophysics, Stanford University \/\/\.-.-....___
  \/    \/    \/Joe Dellinger [e-mail]  apple!hanauma!joe\/\.-._

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

Date: 20 Jul 89 17:54:05 GMT
From: [e-mail]  (Jonathan Patrick Leech)
Subject: Re: latest Quayle gaffe

In article <[e-mail]> [e-mail] (Tom Neff) writes:
>By the way this is only barely sci.space, but I assume folks have heard
>about Danno's latest.

    Perhaps this is a heretical thought, but it seems to me that
Quayle is actually doing a *good job* as chairman of the NSC.  Now,
maybe this is just because it's full of competent people; but even
then, it shows he's listening to them.
--
    Jon Leech ([e-mail])
    Apple Integrated Systems
    __@/

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

Date: 20 Jul 89 22:09:38 GMT
From: [e-mail]  (Peter G. Ford)
Subject: Re: Magellan Status for 07/17/89 (Forwarded)

In article <[e-mail]> [e-mail] (h.munk) writes:
>In article <[e-mail]>, [e-mail] (Peter E. Yee) writes:
>> continues to perform twice daily momentum wheel desaturations
>                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>Forgive me my ignorance, but what is "momentum wheel desaturation",
>and why is it done ?

When mapping Venus by radar, accurate antenna pointing is very
important.  Unlike an optical imager, a synthetic aperture radar is
"pointed" electronically, by choosing a precise time and frequency
"window" within which to listen for echoes. If the antenna isn't
pointing at the correct part of the planet, you don't pick up any
useful data at all!  During each orbit of Venus, the Magellan antenna,
along with the rest of the spacecraft to which it is rigidly attached,
must slowly rotate to trace a line on the planet's surface that follows
the pre-chosen "mapping swath" for that orbit.

Unlike the earlier generation of spacecraft which used small rocket
motors for orientation, Magellan uses a set of three small gyroscopes,
called "momentum wheels", each of which spins along one of three
mutually perpendicular axes. To rotate the spacecraft about one of
these axes, it is necessary to change the rotation rate of that
particular momentum wheel IN THE OPPOSITE SENSE.  Magellan, as an
isolated body, must conserve angular momentumm, and the change in the
angular momentum of the wheel is offset by that of the rest of the
body.  A rotation about an arbitrary axis can be put together out of a
series of rotation changes of any two wheels.  Wheels are better than
rockets because they use only electric power (from the solar panels),
not precious liquid fuel.

But what, you ask, is a "momentum wheel desaturation?" Well, the wheels
are much less massive than the rest of the spacecraft (technically,
their moments of inertia are much smaller), so they must spin up to
very high rates to turn Magellan in a reasonable time. To avoid their
spinning so fast that they fly apart, there are auxiliary rockets on
Magellan that are fired from time to time to give the spacecraft a
strong twist in the opposite direction, thereby allowing the wheels to
be spun down and "desaturated".

The desaturation burns are bad news to those of us interested in the
precise location of the spacecraft--e.g. for the altimetry experiment,
or to determine the shape of the Venus gravity field--because, in
addition to a rotation, they tend to push Magellan sideways by a random
amount which must be allowed for in subsequent data processing. By a
careful combination of wheel turns, the need for desaturation burns is
minimized. Once in orbit, we hope to keep them down to less than one
per day.

Peter Ford
MIT and Magellan Project

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

End of SPACE Digest V9 #572
*******************