Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v13_2/v13_250.txt

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Subject: SPACE Digest V13 #250

SPACE Digest                                     Volume 13 : Issue 250

Today's Topics:
              Magellan Update - 03/08/91
Re: German conference highlights doubts about ESA's manned space plans
                  Re: meteor
                  Re: Thrust
        Re: Wednesday NOVA on PBS: Russian Right Stuff
           Pioneer Venus Update - 03/01/91
               Magellan article
                  Re: meteor
                Solar activity
              Re: Space Profits
             Pioneer 10 Update - 03/01/91
              Magellan Update - 03/05/91

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
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----------------------------------------------------------------------

Date: 9 Mar 91 01:05:06 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan Update - 03/08/91


                          MAGELLAN STATUS REPORT
                             March 8, 1991

     The Magellan spacecraft is performing nominally.  All STARCALS (star
calibraions) and DESATS (desaturations) during the past 24 hours were
successful.

     The spacecraft has now performed 160 days of radar mapping at Venus.
The represents 1172 mapping orbits, covering about 237 degrees of global
longitude or 66% of the distance around the planet.  Magellan will complete
its first mapping cycle on May 15, 1991.

     At the end of the first mapping cycle, the Magellan Project expects to
have high resolution images of more than 80% of the surface of Venus.  Some
of the non-imaged area was expected, such as the South Polar gap and the
portions missed during Superior Conjunction or Apoapsis Occultation.  Other
gaps were the result of spacecraft or telecommunications problems.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      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: 7 Mar 91 17:24:12 GMT
From: agate!stanford.edu!snorkelwacker.mit.edu!usc!cs.utexas.edu!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: German conference highlights doubts about ESA's manned space plans

In article <[e-mail]> [e-mail] (Daniel Fischer) writes:
>... E.Keppler: orbital repairs could only be of such a primitive kind that
>they could be handled by robots as well. The first HUBBLE revisit in late 1993
>might prove him wrong - or not.

The previous repair missions have already proved him wrong.  Not one of them
has gone sufficiently smoothly to be handled by robots.  The Solar Max repair
was nearly a failure because the automatic docking hardware simply didn't
work.  The Palapa/Westar retrieval similarly was done with a heavily-manual
backup procedure after the carefully-prebuilt docking fixtures didn't fit.
The Syncom repair actually worked okay, because no attempt was made to use
machines instead of humans for even the simplest tasks.  Soviet repair work
on Mir similarly has been full of surprises and unexpected difficulties.

Experience so far says very strongly that if you plan to do in-space repairs,
you had better plan to have humans (or the imaginary just-as-flexible
teleoperated robots which will be available almost right away now for sure,
really, trust us) on hand.
--
"But this *is* the simplified version   | Henry Spencer @ U of Toronto Zoology
for the general public."     -S. Harris |  [e-mail]  utzoo!henry

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

Date: 7 Mar 91 22:14:44 GMT
From: [e-mail]  (Heidi Hammel)
Subject: Re: meteor

[e-mail] (Johnathan Vail) writes:
>   [e-mail] (David W Kimball) writes:
>   Last night (March 6, 1991) at about 2:55 AM EST I observed an unusual
>   meteor just as I left the main library here at the University of New
>   Hampshire. [description of meteor deleted]
>   Did any one else see the thing? It was so odd for a meteor, I've wondered
>   if it may not have been something else. Were any satellites or anything
>   falling out of orbit last night? (or would that just look the same as a
>   meteor?)
>
>Well, its hard to say but I would think it was around for too long to
>be a meteor.  Since you are so close to a SAC base I might focus my
>suspicions there.

According to the Boston Globe (7 March 91), this *was* a meteor.  It
was visible from New England, New York, Pennsylvania, and New Jersey.
It was described as a "classic fireball," although this particular
meteor was noted as being unusual due to its brightness, its visibility
over a very large area, and its persistence for a fairly long time.

--
------   Heidi B. Hammel      ([e-mail])     MIT 54-316
--       Department of Earth, Atmospheric, and Planetary Sciences

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

Date: 7 Mar 91 21:49:41 GMT
From: agate!bionet!uwm.edu!cs.utexas.edu!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Thrust

In article <[e-mail]> [e-mail] (Steve Savitzky) writes:
>   ... Basically, solar panels charge a battery that drives a heating
>   element in a water tank that generates steam which is released out a
>   nozzle...
>
>How inefficient!  Why not use solar energy to heat the water directly?

Because the solar panels and batteries have to be there already.  Direct
solar heating requires designing your whole spacecraft around it, and
incidentally only works when you're in sunlight.
--
"But this *is* the simplified version   | Henry Spencer @ U of Toronto Zoology
for the general public."     -S. Harris |  [e-mail]  utzoo!henry

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

Date: 7 Mar 91 23:34:28 GMT
From: [e-mail]  (Adam R. Brody)
Subject: Re: Wednesday NOVA on PBS: Russian Right Stuff

[e-mail] (Kish Shen) writes:

>>Russian Right Stuff

>>A three-part look at the Soviet space program opens with a profile of
>its chief
>>designer Sergei Korolev

>I think this is the "Horizon" (a BBC TV science program) shown here in the UK
>a few months back. If I remember correctly, the commentator was one of the
>regular person used by Horizon, and was British. Does anybody know how this was

The program was definitely Nova put out by WGBH Boston (PBS).

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

Date: 8 Mar 91 21:08:30 GMT
From: rex!wuarchive!sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Pioneer Venus Update - 03/01/91


                       PIONEER VENUS STATUS REPORT
                           March 1, 1991

     At the request of the Magellan project, a 70 meter Canberra track was
swapped for a 34 meter Canberra track on February 22.  This required a change
in the bit rate to 512 bits/second versus the planned 1024 bits/second on the
Pioneer Venus spacecraft.  An 8-degree attitude maneuver and HGA (High Gain
Antenna) adjustment was successfully executed on February 23.  On February 25,
antenna problems at the 70 meter Goldstone station caused a 1 hour and 30
minute loss of telemetry data.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      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: 8 Mar 91 22:50:01 GMT
From: rex!wuarchive!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan article

Los Angeles Times -- 3/6/91
"Magellan Data from Venus is Vast, Complex"
By Lee Dye

"The Magellan spacecraft has responded to more than 80,000
commands and has sent back more bits of data from Venus
than was collected during the entire missions of the Voyager,
Viking and Mariner spacecraft, scientists said Tuesday."

The Times reports that despite images which are telling
scientists more about Venus and its hot, smoldering surface
than the lunar missions told of the moon, planetary scientists
are still disagreeing over the powerful forces which are
molding the tortured surface of Venus.

The article says the volume of data is so staggering and the
geologic processes so complex that the scientific team are
struggling to understand some of the fundamental forces at
work on Earth's twin.

The story tells of images which feature surface effects
described as a folding process similar to that here on Earth
which created the mountain ranges of California.  Other
images, according to the story, depict blotches and smudges on
the surface which seem to indicate activity ongoing even today.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      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: 8 Mar 91 20:04:29 GMT
From: ramona!dg-rtp!lurch![e-mail]  (Peter Brown)
Subject: Re: meteor

|In article <[e-mail]>, [e-mail] (Johnathan Vail) writes:
|
|In article <[e-mail]> [e-mail] (David W Kimball) |writes:
|
|   Last night (March 6, 1991) at about 2:55 AM EST I observed an unusual
|   meteor just as I left the main library here at the University of New
|   Hampshire. It was moving southwest to northeast, and was moving much
|   too quickly to be an aircraft. It was in view for two or three seconds,
|   disappeared behind Thompson Hall, and was then in my view again for about
|   five more seconds before it was lost over the horizon. It was completely
|   silent. I have never seen a meteor like it - though moving very rapidly,
|   it was slow for a meteor. It was blue-white in color, much like Sirius, and
|   did not leave any appreciable trail. In fact, it was rather like watching
|   a -5 or -6 magnitude blue-white star move quickly across the sky.
|   Did any one else see the thing? It was so odd for a meteor, I've wondered
|   if it may not have been something else. Were any satellites or anything
|   falling out of orbit last night? (or would that just look the same as a
|   meteor?)
|
|Well, its hard to say but I would think it was around for too long to
|be a meteor.
|
|Since you are so close to a SAC base I might focus my suspicions
|there.
|
|jv


Nah, Pease Airforce Base is closed, is it not?
Hey, it was nice to picture you standing outside the library, looking at T-Hall.
Brought back memories of some late nights I spent at UNH.

--
Peter Brown -- Data General Corp. --  email: [e-mail]
My views, thoughts, opinions and spelling errors are definitely my own!

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

Date: Fri, 8 Mar 91 20:45:21 EST
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Solar activity


>From: [e-mail] (CARY OLER)
>Subject: MAJOR SOLAR FLARE ALERT - 07 MARCH

>MAJOR ENERGETIC EVENT SUMMARY

>     Three major solar flares exploded from Region 6538 today.  The first
>event was a very powerful proton-type which began at 06:13 UT on 07 March.

I recently put together a setup to photograph sunspots. A few days ago, there
were hardly any. Now a whole swarm of them are starting to come into view.

Beware...

    John Roberts
    [e-mail]

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

Date: Thu, 7 Mar 91 13:53:50 -0500
From: "Allen W. Sherzer" <[e-mail]>
Subject: Re: Space Profits
Newsgroups: sci.space
Cc:

In article <[e-mail]>:

>Launch costs still need to come down enough that off-earth operations
>reduced delta-vee benefits aren't eaten up by immense costs of starting
>them up in the first place.

*OR* we do what we did with railroads, interstate highways, ports, airlines,
and other infrastructure. The government builds the infrastructure and then
leases it to users over a long period of time.

  Allen


--
+-----------------------------------------------------------------------------+
|Allen Sherzer |A MESSAGE FROM THE ANTI-WAR MOVEMENT TO THE PEOPLE OF KUWAIT: |
|[e-mail]   |       "If rape is inevitable, enjoy it!"                     |
+-----------------------------------------------------------------------------+

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

Date: 8 Mar 91 21:05:34 GMT
From: rex!wuarchive!sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Pioneer 10 Update - 03/01/91


                          PIONEER 10 STATUS REPORT
                               March 1, 1991

     On February 20 and 25, predicted RFI (Radio Frequency Interference) at
at the Madrid 70 meter station caused a 55 minute and a 1 hour telemetry
outage, respectively, with the Pioneer 10 spacecraft.  On February 22, antenna
problems at the Goldstone 70 meter station caused a 47 minute loss of
telemetry data.

     On March 1, the Madrid 70 meter antenna was unable to lock up telemetry
at the predicted bit rate of 16 bits/second.  RFI was present, however
analysis of the signal by the station indicated the spacecraft may have been
transmitting at 64 bits/second.  The Goldstone 70 meter antenna supported
a short pass on the same day and was also unable to lock to 16 bits/second,
but reported the SDA (Subcarrier Demodulator Assembly) was in-lock at 64
bits/second.  Ames Research Center sent a bit rate change command back to
16 bits/second to the spacecraft which will be executed on March 2.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      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: 8 Mar 91 22:39:46 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan Update - 03/05/91


                         MAGELLAN STATUS REPORT
                            March 5, 1991

     At about 5:47 PM (PST) on March 4, the fourth in a series of attitude
computer interrupts occurred when the spacecraft had turned away for a star
calibration.  The result was that a series of fault protection actions
occurred during the time the spacecraft was turned away and a relatively
large buildup in pointing error occurred.  This in turn resulted in the loss
of signal for about 2 1/2 hours.

     It was assumed that Magellan had suffered another heart beat timer loss
incident, and was 3 to 4 degrees off Earth point.  No spacecraft emergency was
declared.  At about 8:20 PM (PST) the S-band signal was reacquired.  Commanding
then began to place the spacecraft back to the primary gyro's which provide
more pointing accuracy.  Commands were then sent to regain the desired pointing
accuracy.

     During this whole time the sequence on-board the spacecraft continued to
function.  By 8:00 AM (PST) today a successful star calibration showed that a
pointing accuracy of 0.04 degrees had been achieved and the spacecraft was back
to a good mapping posture.

     As a result of this latest incident, about 3 1/2 orbits of mapping data
has been lost and an additional orbit (Orbit 1634) will have about a 1 degree
pointing error.

     Temperatures during the incident were elevated in several parts of the
spacecraft, but not to dangerous levels.  Temperatures have now returned to
those observed prior to the incident.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      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.

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

End of SPACE Digest V13 #250
*******************