Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_5/V12_551.TXT

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Subject: SPACE Digest V12 #551

SPACE Digest                                     Volume 12 : Issue 551

Today's Topics:
           Re: The great light bulb debate
            Re: Nameplates on space probes
              Magellan Update - 11/12/90
            Re: Creationists and Moon Dust
         Re: Call for new news group : sci.space.seds
LLNL size and Fred micrograv environment (was LLNL astronaut delivery)
               angular momentum
       Re: You Can't Expect a Space Station to be Cheap
              Galileo Update - 11/12/90

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription notices,
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Date: 11 Nov 90 22:08:38 GMT
From: rti!dg-rtp!bigben!bigben![e-mail]  (Philip Gladstone)
Organization: Data General, Development Lab Europe
Subject: Re: The great light bulb debate
References: <[e-mail]>
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In article <[e-mail]> [e-mail] (John Roberts) writes:

   >Modern light bulbs are filled with argon, not vacuum.  (Expensive ones
   >use krypton.)

   As you imply, the old bulbs were evacuated. I believe the main reason for the
   switchover to inert gas was to reduce the rate of evaporation of the
   filament at a given temperature.

In the UK (10 years ago) light bulbs contained *some* gas to about 30%
atmospheric pressure. This is easy to demonstrate by following this
procedure:

1)  Find a light bulb -- preferably a dead one (it'll be useless if
    you complete the rest of these instructions).

2)  Fill a bucket with water.

3)  Find a compass (the drawing instrument) or other sharp spiky
    object.

4)  Use the compass to make a small hole in the metal cap of the bulb.

5)  Hold the bulb under water and push the compass into the metal cap
    and wiggle it around inside. If you do this just right, you will
    break the glass seal that was used to evacuate the bulb.

6)  The water now rushes in to equalise the pressure. You can now
    judge what the pressure was before you broke the seal by how
    much water entered.


WARNING: If you do this wrong you could break the envelope. For this
reason wear gloves.

--
Philip Gladstone
Development Lab Europe
Data General, Cambridge
England.  [phone]

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Date: 11 Nov 90 20:12:26 GMT
From: umich!umeecs!msi.umn.edu!cs.umn.edu!kksys!wd0gol!newave![e-mail]  (John A. Weeks III)
Organization: NeWave Communications Ltd, Eden Prairie, MN
Subject: Re: Nameplates on space probes
References: <[e-mail]>, <[e-mail]>, <[e-mail]>
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In article <[e-mail]> [e-mail] (Daniel Briggs):
> In article <[e-mail]> [e-mail] (Peter Sultan):
> > There have been several `nameplates' on US space probes.

> C'mon, Peter, the moon is right next door!  We may well never see the
> Voyagers again

I would be surprised to see a Voyager in the Smithsonian in 50 years, but
100 years might not be unreasonable.  If us earthlings pooled our expertise
and money, as we might someday do, travel within the solar system will be
within reach.  A Voyager might be scientifically interesting from the
standpoint of examining a man-made object that was exposed to outer solar
system space for a long time.  Sort of like LDEF without any tomatoes.

> If the world gets its collective act together, that site may well be
> a *shrine*, a century from now.  It's not even completely outlandish
> that someone reading this message might one day read that plaque.

Put a dome over the thing and build the Smithsonain-Disney Moon Theme Park
around it!

-john-

--
===============================================================================
John A. Weeks III               [phone]               [e-mail]
NeWave Communications                ...uunet!rosevax!bungia!wd0gol!newave!john
===============================================================================

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Date: 12 Nov 90 22:05:02 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Subject: Magellan Update - 11/12/90
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                        MAGELLAN STATUS REPORT
                          November 12, 1990

     The Magellan spacecraft performance is nominal.   The spacecraft
successfully accepted commands on Friday, November 9, resuming mapping on
orbit 787 at 4:07 am PST on Saturday, November 10.  One STARCAL (star
calibration) occurs every orbit and 1 DESAT (desaturation of the reaction
wheels) every 4th orbit.  16 STARCALS and 4 DESATS have been done since
mapping resumed.

     A sequence patch to disable solar array control during mapping has
prevented the spacecraft vibration from recurring.  Track 1 of tape recorder B
was successfully played back on November 9.  It contains the results of
STARCALS performed during Superior Conjunction.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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Date: Mon, 12 Nov 90 10:41:20 PST
From: [e-mail]
X-Vmsmail-To: UTADNX::UTSPAN::AMES::"[e-mail]"
Subject: Re: Creationists and Moon Dust
To: [e-mail]

In Subject: SPACE Digest V12 #525,
optilink![e-mail]  (Clayton Cramer) writes:

>In article <s64421.657561762@zeus>, [e-mail] (house ron) writes:
>> Creationists around here are claiming that before the moon shots,
>> scientists were worried about the space craft sinking in metres of
>> dust which they thought should have accumulated since the moon was
>>...(stuff deleted)
>> Ron House.   ([e-mail])

>I've given up trying to intelligently argue with "creation
>scientists".  When I get the energy, I will be posting a review
>of a wonderful book for dealing with creationists called _The_
>Fingerprint_Of_God_, written by a guy with a Ph.D. from University
>of Toronto in astrophysics...
>...(more stuff deleted)
>Clayton E. Cramer {pyramid,pixar,tekbspa}!optilink!cramer

This is straying pretty far from immediate Space Digest concerns, but I
thought everybody might like to know that the 16 year reign of Creationists
in the selection of Texas schoolbooks has been broken!  This is important to
the rest of the country because (for some reason) most states follow the
Texas lead in schoolbook selection.  Previously, Texas science textbooks
were required to give equal treatment to creationism and evolution, with the
result that there was very little about evolution and some textbooks dropped
both subjects altogether.  Last year the Texas schoolbook selection
committee voted to include creationist objections to evolution only if they
were rational and scientific, with the result that the new textbooks
selected last week have no mention of creationism at all.
    Moral: if you keep at it long enough, and you get help in high
places (in this case the Texas attorney general and H. Ross Perot), you can
turn what seems a hopeless situation around.  Maybe that will go for the US
space effort too.

_____________
Dale M. Greer, whose opinions are not to be confused with those of the
Center for Space Sciences, U.T. at Dallas, UTSPAN::UTADNX::UTDSSA::GREER
      While the Bill of Rights burns, Congress fiddles. -- anonymous

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Date: 12 Nov 90 15:58:40 GMT
From: mcsun!ukc!icdoc!syma![e-mail]  (Nick Watkins)
Organization: University of Sussex
Subject: Re: Call for new news group : sci.space.seds
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From article <[e-mail]>, by [e-mail] (M.S.Bennett  Supvs= Prof Pendry):
> founded 10 years ago to put pressure on congress to uncancel a number of
> probe missions - in this it was successful.
Which ones ? I know Planetary Society was involved in lobbying for
Galileo & Mars Observer - what exactly did SEDS do ?

Nick
--

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Date: 9 Nov 90 22:17:28 GMT
From: mips!zaphod.mps.ohio-state.edu!samsung!umich!sharkey!cfctech!teemc!fmeed1![e-mail]  (Russ Cage)
Organization: Ford Motor Co., Electronics Div., Dearborn, MI
Subject: LLNL size and Fred micrograv environment (was LLNL astronaut delivery)
References: <[e-mail]>, <[e-mail]>, <[e-mail]>
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In article <[e-mail]> [e-mail] (Charles Radley) writes:
>In <[e-mail]>, Allen Sherzer wrote:
>+Actually, it makes micorgravity better. By putting the microgravity
>+facility in a crew-tended free flyer it won't be subjected to the
>+vibration which Freedom will subject it to.
>-
>True, but it won't benefit from continuous manned presence to fix
>problems.

Continuous manned presence *is* a problem for microgravity research.
So is a shifting CG, which moves the experiments into regions of
greater or lesser tidal force.

This is not a benefit, it is a liability.  Ask the micrograv
researchers.  A free-flyer can be tailored to the job, and
does not suffer from vibration or CG shifts on the station proper.

>           For a free-flyer to  fly "in-formation" with a nearby
>manned base will require frequent disruptive thruster pulses, so it
>is not totally quiet.  Otherwise it would have to rely on nodal
>regression to rendezvous with a station, with weeks or months of no
>human access.

On a free-flyer, thruster pulses can be scheduled to coincide with
dead time, furnace re-loads, and so forth.  It may mean a delay
between the time something breaks and the time it can be fixed,
but if something is broken you don't care about giving it a bit
of gee, there is no processing to be disturbed.  On a manned
platform, you are going to have vibration any time the crew is
moving around, which will be much of the time.  There is work
which cannot be done on a manned platform, and the Fred design
doesn't allow for it at all.
---------------------------------------------------------------
And now for the part I find confusing.  This posting brings an
apparent contradiction into sharp focus, because it holds both
parts of it in more detail than ever before in this discussion:

#1:
>What commercial needs ? It puzzles me why people such as yourself
>prefer a small station to a big one.

Here you are apparently saying that the LLNL station would be
smaller than Fred, but then you say...

#2:
>+Two Titans gives you more interior room than Freedom.
>-
>Interior volume is not particularly exciting, except for recreation.
>Maybe useful if we ever get a space tourism industry up and running.
>Right now more interested in maximum science for minimum weight and
>cost.

There you admit that LLNL would have more volume than Fred (and
thus more room for equipment).  Well, which is it?  Or were you
talking about Fred in #1, and not LLNL?  If so, I'm sure there
is an answer to your question.
--
Russ Cage    Ford Powertrain Engineering Development Department
Work:  itivax.iti.org!cfctech!fmeed1!cage   (CHATTY MAIL NOT ANSWERED HERE)
Home:  [e-mail]  (All non-business mail)
Member:  HASA, "S" division.

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Date: 12 Nov 90 13:50:11 GMT
From: swrinde!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!watserv1!ria!uwovax![e-mail]
Subject: angular momentum
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Angular momentum in a system evolving towards synchronous rotation:

    Angular momentum has to be preserved - several people pointed this
out - and it is. As the total rotational angular momentum changes due to
slowing of rotation (on both bodies), the orbital characteristics of the
system change in step. For instance, right now the Moon is in synchronous
rotation, but Earth is not (the fully evolved system is that of Pluto and
Charon, both rotating synchronously with their orbital motion with respect
to each other). Therefore the Moon brakes the Earth, and the angular momentum
which is lost from Earth's slowing is made up by an increase in the Moon's
orbital radius.

Phil Stooke,
Department of Geography,
University of Western Ontario,
London, Ontario, Canada N6A 5C2

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Date: 12 Nov 90 18:49:08 GMT
From: swrinde!zaphod.mps.ohio-state.edu!samsung!rex!rouge![e-mail]  (Fraering Philip)
Organization: Univ. of Southwestern LA, Lafayette
Subject: Re: You Can't Expect a Space Station to be Cheap
References: <[e-mail]>, <[e-mail]>
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The following exchange has taken place:

Russ Cage:



Russ Cage had written:
RC>Show me anything like SSX which has flown even 2 flights, and
RC>come within a factor of 2 of its cost target.

And I had responded:

PF>Well, for starters, Max Hunter, SSX's main proponent, says that it is
PF>less complex than a major airliner.

To which Russ said:

RC>1.)    Has it flown?  No.
RC>2.)    Has it come within 2x its cost targets?  Unbuilt, so we don't know.

And goes on in a similar fashion, best summarized by his summary
line:

RC>Summary: SSX is still a paper vehicle, and cannot be compared to expendables.

You don't get it. I am saying that we should put our trust in people
who have had success with launch technology before. Like Hunter, who
allegedly built the Delta, which everyone talks about as a raging
economic success. SSX basically has the same payload-to-weight ratio
as Delta, but is reusable. Twenty years of advances in _structures_
(and computer design, computer control, manufacturing advances, and
aerodynamics ought to enable us to use the H-2 or RL-10 in a
reusable manner. It's not operational now, but if we start on it now
we might have an operational vehicle by the time Freedom goes up.
And given probable design changes in Freedom, such as the downsizing
of the modules which might be about to take place due to center-of-gravity
restraints on the shuttle (even a stripped full-size module allegedly
fails this), Freedom could launch on SSX and the Shuttle, and we would
have a backup system for the station.

Phil

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Date: 12 Nov 90 20:00:10 GMT
From: usc!elroy.jpl.nasa.gov!forsight!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Subject: Galileo Update - 11/12/90
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                         GALILEO STATUS REPORT
                           November 12, 1990

     A command was sent today to the Galiloe spacecraft to reset the command
loss timer to 216 hours, the planned value for this mission phase.  Another
delta DOR (Differential One-way Ranging) navigation activity was successfully
completed today using using the 70 meter antenna pairs at Goldstone/Spain and
Goldstone/Australia.  The sequence memory load for TCM-7 (Trajectory Course
Maneuver 7) will be sent to the spacecraft today.  The spacecraft will execute
the maneuver tomorrow using its axial and lateral thrusters.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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End of SPACE Digest V12 #551
*******************