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Subject: SPACE Digest V12 #509

SPACE Digest                                     Volume 12 : Issue 509

Today's Topics:
          RE: Martian Canals - when did theory die?
           Payload Status for 10/26/90 (Forwarded)
             Re: Antenna heating
              Magellan Update - 10/29/90
               Re: Hiten Update
             FTP sites for space images??
             Re: Theory for Life
        Re: A great idea on how to fund NASA!
                  Re: Hubble
            Re: Magellan Update - 10/26/90
          Re: Martian Canals - when did theory die?

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription notices,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

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

Date: 29 Oct 90 22:13:37 GMT
From: [e-mail]  (PAUL FOSTER LOWELL)
Subject: RE: Martian Canals - when did theory die?


>A the start of this century an astronomer (Lowell I think) promoted
>the theory of there being canals on Mars.  Was this accepted by many
>other astronomers at that time?  When did this belief cease to be
>head by any astonomers?

At first, Percival Lowell's theory was flatly rejected by the astro-community.
I mean, who would believe that there were large three armed creatures driving
around the surface of Mars on bulldozers!

Shortly after Lowell's death (and the immediate discovery of 'his planet'
Pluto), his theory gained limited respect.  His observations of Mars were
recorded in great detail.  Much of his data was found to be extremely
accurate (for his limited equipment and funding).

Later, maybe the 1950's, astronomers started noticing that atmospheric data
from Lowell's papers did not match spectral readings.  Oxygen levels,
in particular, were not as high as assumed.

Oh well...  The rest was left up to the Viking missions.
By the way, nothing was really concluded from Viking's 'life' detectors!
For some of us, the theory hasn't died.
(No folks, let's not start a fight over this subject again)


---------------------------------------------------------------------
     Paul F. Lowell                  [e-mail]
                          ^^ Oooh, new system
                              GO WOLFPACK!
      .
   *    .        "Ole' Uncle Percy had his Pluto . . .

     ...                 Nemisis is MINE!!!"
     ;
    .    *                    -Me    :-)

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

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

Date: 29 Oct 90 23:37:28 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Payload Status for 10/26/90 (Forwarded)


    Daily Status/KSC Payload Management and Operations 10-26-90.


    - STS-35 ASTRO-1/BBXRT (at Pad-B)

    BBXRT liquid argon servicing will be performed today.
    Experiment monitoring continues.


    - STS-38 DoD MMSE support (at SPIF)

    The canister will be transported to Pad-A and lifted to the
    PCR today.


    - STS-39 AFP-675/IBSS/STP-01 (at CCAFS)

    CITE preps and ground software development continue.  Cirris
    cryo servicing will also be active today.

    - STS-40 SLS-1 (at O&C)

    Module closeouts continue along with MVAK training.


    - STS-37 GRO (at PHSF)

    Functional testing will be performed today.


    - STS-42 IML-1 (at O&C)

    Module and experiment staging will continue today.


    - STS-45 Atlas-1 (at O&C)

    Experiment and pallet staging continue.


    - STS-46 TSS-1 (at O&C)

    Experiment and pallet staging will continue today.


    - STS-47 Spacelab-J (at O&C)

    Rack and floor staging continues.


    - STS-67 LITE-1 (at O&C)

    No work is scheduled for today.

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

Date: 30 Oct 90 00:19:33 GMT
From: unmvax!nmt.edu![e-mail]  (Daniel Briggs)
Subject: Re: Antenna heating

In article <[e-mail]> [e-mail] (John Roberts) writes:
>
>>From: att!cbnewsl![e-mail]  (Stuart Warmink)
>>Subject: Re: Magellan Update - 10/26/90
>
>>As the Sun lies pretty much in between Magellan and Earth, won't the
>>dish antenna be rather effective at focussing the Sun's light and heat
>>at the secondary reflector and perhaps even the receiver/transmitter?
>>I guess it all depends on how good the dish's surface is at reflecting
>>those wavelenghts without scattering. Is the surface shiny?
>
>My boss says this problem can also affect satellite dishes, at least a few
>days per year. Note that burning or melting is not the only problem: high
>temperatures can shorten the lifetime of electronics (by encouraging the
>migration of substances that shouldn't migrate?)

You aren't just whistling dixie here, guys.  I used to work for the
Caltech solar astronomy department, which operates a pair of 90 ft
antennas as a solar interferometer.  About a year before I arrived
there, they had a bad run in with this problem.  It snows in the
winter at OVRO.  The weather conditions happened such that a light
powder of snow accumulated on the dishes, but not heavy enough to
trigger a snow dump.  The temperature rose high enough that so that
the powder snow barely melted, and then dropped again.  The result was
a very thin and uniform coating of ice on the dish surface.  It's a
*solar* interferometer, (and a prime focus system to boot), so it was
naturally pointed directly at the sun.  We basically turned the dishes
into 90 ft diameter solar furnaces.  I have seen photographs of the
receiver packages.  They looked a lot like someone had attacked them
with a blowtorch.  Very black, and very charred!  I don't think that
they were completely written off (we were on a very limited budget,
after all), but they certainly had to be rebuilt from the ground up.
They added prime focus temperature sensors after that.  These sensors
did in fact later trigger a stow a few times, but of course the stow
threshold was set considerably lower than the original disaster.  I
have heard a few similar horror stories from other antennas, but I
would be hard pressed to back them up with references.

--
This is a shared guest account, please send replies to
[e-mail] (Internet)  ["Life's a Beech, and then you Dive."]
Dan Briggs / NRAO / P.O. Box O / Socorro, NM / 87801  (U.S. Snail)

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

Date: 29 Oct 90 17:42:24 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan Update - 10/29/90


                         MAGELLAN STATUS REPORT
                           October 29, 1990


     Radar mapping was suspended on October 26, at 6:23 AM PDT, for Superior
Conjunction.  This suspension will last for approximately 12 days until early
November, while Venus and the spacecraft pass behind the Sun as viewed from
Earth.  Earliest mapping start-up date is November 7.

     The spacecraft will keep its High Gain Antenna pointed directly toward
Earth throughout the Superior Conjunction period, so as to permit the
transmission of engineering telemetry at 40 bps and the reception of commands
from Earth.  It will turn away from Earth only to perform star scan maneuvers
in order to update its inertial reference sensors.  This attitude will shade
the spacecraft's electronics from the Sun and keep the temperature cool.
Telemetry and commanding should be possible throughout Superior Conjunction.

     During the Superior Conjunction period, modifications and testing to the
spacecraft software will be developed to prevent the oscillations which have
been observed in the Solar Arrays.  Although this oscillation does not present
an immediate threat to the spacecraft, stopping it will prevent any long term
fatigue of the Solar Array mechanism.

     Since September 15, Magellan has performed 40 days of radar mapping,
producing 301 image strips covering 60 degrees of longitude around Venus.  The
mission has thus already covered roughly 1/6 of the planet.

     A status review of Attitude Control software fixes will be held in Denver
on October 31.  The next press conference to be held on November 16 at JPL
will focus on images of Ishtar Terra.  A mission planning review for the 2nd
cycle, the first extended mission cycle of 243 days starting on April 29,
1991, will be held on November 29.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 29 Oct 90 12:01:38 GMT
From: eru!hagbard!sunic!mcsun!unido!mpirbn![e-mail]  (Daniel Fischer)
Subject: Re: Hiten Update

Reply-To: [e-mail] (Daniel Fischer)
Organization: Max-Planck-Institut fuer Radioastronomie, Bonn

In article <[e-mail]>
   [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Andy Clews) writes:
>>please post some summary information about the mission objectives for
>>the Hiten craft? ...
>
>Mission objectives are to test Japanese navigation and control facilities
>for spacecraft operating beyond low Earth orbit.  Period.  It is an
>engineering mission with no attempt at science return.

Wrong! There is one scientific instrument on-board, the MDC = Munich Dust
Detector from the Techn.Univ. of Munich. It's aperture can be seen on most
photographs of Hiten as a little square-shaped gap in the solar cells of the
main body. This little experiment is continuosly returning data on dust impacts;
since the aperture is quite small, there is only one impact per week or so, but
the one discovery has already been made (and was even mentioned in the Space
News newspaper): micrometeorites coming from the direction of the sun. These
particles (called beta-meteorites, not 'beta-particles' as Space News said -
they aren't radioactive!) are dust grains so tiny that the solar radiation
pressure is stronger on them than gravity -> they spiral outwards. The same
physics as in cometary dust tails.

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

Date: 29 Oct 90 23:06:37 GMT
From: sdd.hp.com!uakari.primate.wisc.edu!uflorida!beach.cis.ufl.edu![e-mail]  (Wade Hebert)
Subject: FTP sites for space images??

I am new to this newsgroup and have not found what I need;  namely, a list
of FTP sites that have any images taken from any space probes, past or
present.  If anyone has a list of such sites, would you please E-mail a
copy to me?  I would be most appreciative.  Sorry to waste bandwidth on
a question that may have already been addressed.

Thanks in Advance,

Jack J. Thompson    [e-mail]

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

Date: 29 Oct 90 21:10:23 GMT
From: sdd.hp.com!zaphod.mps.ohio-state.edu!samsung!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!watserv1!maytag!watdragon!watyew![e-mail]  (Brian or James)
Subject: Re: Theory for Life

In article <[e-mail]> [e-mail] (David Palmer) writes:

    [material deleted]

>Obviously, the next step in evolution is to shed symmetry altogether.

    *What* 'next step'? The history of evolution on Earth is not
a record of lower organisms endlessly striving to achieve 'higher rungs
on the ladder of life [Upper rung usually defined as 'Most like the
writer of the essay in question']. The phrase 'next step' suggests to me
a predesign or goal that life strive to attain, and I don't think the evidence
supports this view of evolution.

                            James Nicoll

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

Date: 29 Oct 90 19:44:39 GMT
From: munnari.oz.au!uhccux![e-mail]  (Jeff Goldader)
Subject: Re: A great idea on how to fund NASA!

Waaay back in '83 or so, NASA put lots of USnail Express Mail First
Day covers in space on STS-8, Challenger's 3rd flight.  I seem to
remember they took about 250,000 up in Get-Away Special cannisters.
A bunch were ruined for some reason, and I was happy when mine arrived
in perfect condition.  It came with a glossy folder with some beautiful
pictures of the launch (it was the first shuttle night launch).

I don't know if anybody actually made any money off the promotion, but
it was a nice idea.

Jeff Goldader                        University of Hawaii
[e-mail]      Institute for Astronomy

"It was the Lone Biker of the Apocalypse..."

Disclaimer: They don't know what I say, I don't care what they think, and
we're all happy that way.

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

Date: Tue, 30 Oct 90 00:56:25 EST
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Re: Hubble


>From: uvaarpa!murdoch!astsun.astro.Virginia.EDU![e-mail]  (Greg Hennessy)
>Subject: Re: Hubble

>John Roberts writes:
>#I think NASA generated a lot of
>#trouble for itself by releasing certain premature conclusions. That might
>#have been a good time to hedge claims, and say "we'll have a more definitive
>#answer in a few days".

>Strange, but when the bad news came out, I heard plenty of pissed off
>people saying, "NASA has known that the mirrors were busted for TWO
>WEEKS without telling us! Why they are trying to cover this up!"

(Of course they knew that the focus was bad, but they hoped it was just
because of poor positioning, which could be corrected by remote commands.)

>-Greg Hennessy, University of Virginia
> USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
> Internet:      [e-mail]
> UUCP:        ...!uunet!virginia!gsh7w

I think that's why they did it that way - they wanted to avoid any appearance
of a coverup, so they went a little too far in the other direction. It's
certainly not easy to choose a good balance between getting the news out
in a timely manner and making sure it's accurate. But several definite
statements were made ("instrument xx will not be usable") that later had to
be recanted. Something like "we haven't yet thought of a way to use instrument
xx with this problem, but we're working on it" might have generated less rage.
     John Roberts
     [e-mail]

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

Date: 29 Oct 90 16:54:49 GMT
From: usc!samsung!noose.ecn.purdue.edu!mentor.cc.purdue.edu!mace.cc.purdue.edu![e-mail]  (Perry G Ramsey)
Subject: Re: Magellan Update - 10/26/90

In article <[e-mail]>, [e-mail] (Stuart Warmink) writes:
> Won't the dish antenna be rather effective at focussing the Sun's light and heat
> at the secondary reflector and perhaps even the receiver/transmitter?
> Is the surface shiny?

The surface isn't shiny in the solar wavelengths.  Visibly, it is white and
diffuse.  There will be some concentration, but it won't focus sunlight like
a telescope.

This is another manifestation of the sometimes nice phenomenon that
things look different to different wavelengths of electromagnetic energy.
Typically, things tend to be more specular to longer wavelengths.
--
Perry G. Ramsey           Department of Earth and Atmospheric Sciences
[e-mail]   Purdue University, W. Lafayette, IN USA
[e-mail]    Congress thinks that if you have nine women pregnant
              simultaneously, you can get one baby in one month.

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

Date: 29 Oct 90 21:50:19 GMT
From: hub.ucsb.edu!ucsbuxa![e-mail]  (Charles Frank Radley)
Subject: Re: Martian Canals - when did theory die?

In article <[e-mail]> [e-mail] (William Coyne) writes:


>A the start of this century an astronomer (Lowell I think) promoted
>the theory of there being canals on Mars.  Was this accepted by many
>other astronomers at that time?  When did this belief cease to be
>head by any astonomers?

>Replies can be sent by email to -

>JANET: [e-mail]
>UUCP : ...!ukc!newcastle.ac.uk!W.P.Coyne
>ARPA : [e-mail] telescopes became bigger and better, the lack of confirmation of Lowell's findings became more and more obvious.
The final nail in the coffin was the Mariner-$ space probe flyby
in 1964. (Mariner-4 that is).

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

End of SPACE Digest V12 #509
*******************