Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_4/V12_472.TXT

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Subject: SPACE Digest V12 #472

SPACE Digest                                     Volume 12 : Issue 472

Today's Topics:
          Magellan/Superior Conjunction (Forwarded)
             Re: Theories needed on life
               Re: PLUTO AND PIONEER 10
             Re: Theories needed on life
    DoD Using Non-crypto GPS Receivers in Operation Desert Shield
           Re: Pioneer 11 Update - 10/17/90
              Magellan Update - 10/19/90
             Re: Theories needed on life
              Re: Deep Lunar Dust Story?
          Re: landform names and soviet/Venus images
       Re: You Can't Expect a Space Station to be Cheap
             Re: Homebuilt Manned Rockets
                 Hiten Update

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: 19 Oct 90 22:19:59 GMT
From: swrinde!zaphod.mps.ohio-state.edu!sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan/Superior Conjunction (Forwarded)

MAGELLAN TO TEMPORARILY HALT RADAR MAPPING OF VENUS

     Nature will force Magellan Project flight controllers at
NASA's Jet Propulsion Laboratory, Pasadena, Calif., to
temporarily halt radar mapping of the surface of Venus in early
November as Venus and Earth near their maximum distance with the
sun in between.

     The maximum distance between the planets, called superior
conjunction, occurs Nov. 1.  The sun and Venus will be less than
1 degree apart.  While Venus will not actually go behind the disc
of the sun, its nearness to the sun from Earth's point of view
will cause radio signals passing close to the sun to degrade.
JPL controllers will still be able to communicate with Magellan
periodically.

     The time of superior conjunction was known and planned for
early in the Magellan mission planning.

     Loss of the radio link at the S-band frequency, which
transmits telemetry to Earth stations through the high-gain
antenna at 1200 bits per second (bps), is predicted for Saturday
when the angle between Venus and the sun, measured from Earth,
narrows to 3.4 degrees.

     But another Magellan radio frequency, called X-band, is
degraded less by the hot plasma around the sun, and controllers
said they expect to be able to command the spacecraft by X-band
each day through more than a week of superior conjunction.

     Use of X-band for the uplink started on Saturday, Oct. 13.
Its use both to and from the spacecraft is predicted to last
until Oct. 27.  The radio downlink rate is 268 kilobits per
second (kbps).

     Solar activity will determine how much the radio signals
degrade and how long mapping will be halted.  Magellan project
officials will make go or no-go decisions on mapping on a day by
day basis.

     On Oct. 29, the spacecraft's computer automatically will
halt mapping for at least 9 days.  The mapping could be halted
for as long as 2 weeks, however, depending on solar activity.  If
solar activity is very heavy, fight controllers will switch
earlier into the spacecraft's computer sequence by ground
command.

     The first standard mapping sequence at 268 kbps, with
telemetry communication with Earth at 1200 bps, is scheduled to
resume on Nov. 21.

     Magellan is managed by JPL for the Office of Space Science
and Applications, Wash., D.C.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 19 Oct 90 23:26:39 GMT
From: sdd.hp.com!zaphod.mps.ohio-state.edu!usc!srhqla!demott![e-mail]  (Kevin D. Quitt)
Subject: Re: Theories needed on life

In article <[e-mail]> [e-mail] (Michael McNeil) writes:
>
>It's highly likely that humanoid life wouldn't exist even on a planet
>just like the Earth -- if life were to independently evolve again.
>There are just too many other possible pathways for it to follow.

    Either that, or the humanoid form is like a chaotic attractor, and
almost all evolutionary forms end up with it - which seems a whole lot
more likely to me.  (Not that I feel it's all that wonderful, I just
don't see anything wrong with it, and I doubt we're really all that
special).

--
 _
Kevin D. Quitt         demott!kdq   [e-mail]
DeMott Electronics Co. 14707 Keswick St.   Van Nuys, CA 91405-1266
VOICE [phone]   FAX [phone]  MODEM [phone] PEP last

                96.37% of all statistics are made up.

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

Date: 19 Oct 90 18:25:04 GMT
From: hplabsb![e-mail]  (David Smith)
Subject: Re: PLUTO AND PIONEER 10

In article <17109021:33:[e-mail]> CK02@Lehigh writes:
>To elaborate, Pioneer 10 or 11 (or the Voyagers), didn't go on to Pluto
>because they took trajetories which concentrated their studies on the
>satilities of Saturn (for Pioneer 10 and 11 and Voyager 1) and of
>Neptune for Voyager 2.

Pioneer 10 did not go to Saturn.  Voyager 2 couldn't have gotten to Pluto
from Neptune, so why not visit Triton?

--
"Some fear that Newtonian physics    | David R. Smith, HP Labs
governs superpower relations:        | [e-mail]
What goes up must come down."        | [phone]
    Time Magazine, interviewing Gorbachev, June 4, 1990

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

Date: 20 Oct 90 16:53:17 GMT
From: usc!srhqla!demott![e-mail]  (Kevin D. Quitt)
Subject: Re: Theories needed on life

In article <[e-mail]> [e-mail] (Jenni Sheehey) writes:
>It really *is* unlikely that anything even resembling *any* species
>presently on earth would be found on another planet by chance...

    Unless you actually have proof of this, please label it as opinion.
Based on our profound lack of knowledge, it is equally likely that *most*
earth-like planets would develop humanoid life.
--
 _
Kevin D. Quitt         demott!kdq   [e-mail]
DeMott Electronics Co. 14707 Keswick St.   Van Nuys, CA 91405-1266
VOICE [phone]   FAX [phone]  MODEM [phone] PEP last

                96.37% of all statistics are made up.

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

Date: Sat, 20 Oct 90 14:52:50 ADT
From: [e-mail]
Subject: DoD Using Non-crypto GPS Receivers in Operation Desert Shield
Apparently-To: <[e-mail]>

The Department of Defense has purchased 2100 Trimble Navigation
Pathfinder GPS receivers and sent them to the Middle East for use in
operation Desert Shield.  Since the Pathfinder  is an SPS receiver, this
large purchase could be one of the reasons why Selective Availability on
the Block II satellites was turned off around the 10th of August.

(Source: James Stowell, UNAVCO)

================================================================================
 Richard B. Langley                            BITnet: [e-mail] or [e-mail]
 Geodetic Research Laboratory                  Phone:  [phone]
 Dept. of Surveying Engineering                Telex:  014-46202
 University of New Brunswick                   FAX:    [phone]
 Fredericton, N.B., Canada  E3B 5A3
================================================================================

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

Date: 19 Oct 90 03:18:41 GMT
From: news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Pioneer 11 Update - 10/17/90

In article <[e-mail]> [e-mail] (james.f.burnell) writes:
>>      The Pioneer 11 spacecraft emergency continues...
>Was the loss of the Pioneer 11 signal at this time expected, considering the
>age of the spacecraft (loss of output of the RTG), limited power of its
>transmitter and its extreme distance? ...

No.  Something's wrong.
--
The type syntax for C is essentially   | Henry Spencer at U of Toronto Zoology
unparsable.             --Rob Pike     |  [e-mail]   utzoo!henry

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

Date: 19 Oct 90 20:20:52 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan Update - 10/19/90


                    MAGELLAN STATUS REPORT
                      October 19, 1990

     The Magellan spacecraft has now completed 250 mapping orbit.  The 6 of
the 8 STARCALS (star calibrations) and 2 DESATS (desaturations of the
reaction wheels) of the past 24 hours were successful with nominal attitude
updates.  The two partially updates were caused by foreground filter star
rejections.  All spacecraft systems are performing nominally.

     Spacecraft engineers are now nearly certain that the gyro and solar
array position miscompares are caused by torsional oscillations during each
mapping pass.  Deflections of the panel tip, where the sun sensors are located,
may be causing out-of-phase feedback in the control loop.  The oscillation is
not serious enough to stop mapping, but the system engineers are analyzing any
possible impact on radar performance and the likelihood of any long term
fatigue effects.

     The control sequences and fault protection parameters for the period of
Superior Conjunction were sent to the spacecraft yesterday evening.  The
battery charging control was also changed now that the spacecraft is out
of sun and earth occultations.

    The radar system continues to operate normally, but there is some concern
regarding the rate of zero-filled experiment data records.  For example, nearly
32% of the SAR (Synthetic Aperture Radar) bursts on orbit #612 on Monday,
October 15, were zero-filled.  Several tests are being performed on the
received radar data and some temporary modifications to data processing
methods are being considered to alleviate the adverse effects of the degraded
data quality.

     The primary SAR processor is back in operation and four new image swaths
were processed after the repair was completed yesterday evening.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 19 Oct 90 22:18:34 GMT
From: psuvm![e-mail]  (Jenni Sheehey)
Subject: Re: Theories needed on life

In article <[e-mail]>, [e-mail] (Michael
McNeil) says:
>In article <[e-mail]>
>[e-mail] writes:
>>Could someone theorize on what humanoid life would be like on a planet
>>3 or 4 times the size of the Earth.  I'm looking for theories on body
>>structure, societies, technology, psychology, etc.  Thanks, I appreciate
>>any speculation.
>
>It's highly likely that humanoid life wouldn't exist even on a planet
>just like the Earth -- if life were to independently evolve again.
>There are just too many other possible pathways for it to follow.

Sounds like someone wants to write an SF story!  =)
Perhaps a more useful thing to do would be to try to figure out how
humans would change over a long period on time on such a planet...
It really *is* unlikely that anything even resembling *any* species
presently on earth would be found on another planet by chance...

                                                   --Jenni
/-------------------------------------\ ********************************
| JMS111@PSUVM - Bitnet               | * It's life, Jim, but not as   *
| [e-mail] - Internet     | * we know it. --"Bones" McCoy  *
| These opinions are not the property \ ********************************
| or responsibility of Penn State or the Center for Academic Computing |
\----------------------------------------------------------------------/

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

Date: 18 Oct 90 23:41:11 GMT
From: van-bc!rsoft!mindlink![e-mail]  (Bruce Dunn)
Subject: Re: Deep Lunar Dust Story?


     The classic Lunar Dust story is "A Fall of Moondust", a novel by Arthur C.
Clarke.  A lunar transport vehicle full of people disappears inside a "pool" of
dust, fluidized by electrostatic repulsion between particles.  The novel
concentrates on how the trapped people react, and how they are eventually found
and rescued.  A good read.
--
Did you hear the joke about the scientist whose wife had twins?
    - He baptized one and kept the other as a control.

Bruce Dunn   Vancouver, Canada    [e-mail]

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

Date: 20 Oct 90 07:05:02 GMT
From: swrinde!zaphod.mps.ohio-state.edu!samsung!umich!umeecs!msi.umn.edu!cs.umn.edu!sialis!orbit!pnet51![e-mail]  (S Schaper)
Subject: Re: landform names and soviet/Venus images

Well, if such names are offensive either a) `University of Western Ontario' is
also offensive and should be latinized or b) They should have gotten there
ahead of us, if it is that big a deal to them. :-)

Please look at the Magellan images and compare with the Venera. Should be
interesting. Maybe you could post anything intersting, or anything Venera
shows that PIoneer Venus did not, that we should be interested in, esp with
Magellan mapping now.


UUCP: {amdahl!bungia, uunet!rosevax, chinet, killer}!orbit!pnet51!schaper
The necktie is a device of Mordor
ARPA: crash!orbit!pnet51![e-mail]
INET: [e-mail]

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

Date: 20 Oct 90 06:45:13 GMT
From: swrinde!zaphod.mps.ohio-state.edu!samsung!umich!umeecs!msi.umn.edu!cs.umn.edu!sialis!orbit!pnet51![e-mail]  (S Schaper)
Subject: Re: You Can't Expect a Space Station to be Cheap

fascinating, so if we delayed Fred one year, we could build LLNL's station
first
for a control :-)
  IF it works, why build fred?

Unless we need a new station, then modify the LLNL


UUCP: {amdahl!bungia, uunet!rosevax, chinet, killer}!orbit!pnet51!schaper
The necktie is a device of Mordor
ARPA: crash!orbit!pnet51![e-mail]
INET: [e-mail]

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

Date: 18 Oct 90 21:40:52 GMT
From: ubc-cs!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Homebuilt Manned Rockets

In article <[e-mail]> [e-mail] (Patrick J Draper) writes:
>I'm sure it would be MUCH more complex than building and operating a jet
>plane...

Not obvious.  Aerodynamics are lots of fun; rockets have the enormous
advantage of not having to worry about that much.

>Rocket fuel is more explosive than jet fuel.

Uh, nope, sorry.  RP-1, one of the common rocket fuels, *is* jet fuel
in all but the finest details.  And neither one is in the same league,
for safety problems, as gasoline.  The hazard of rockets is that they carry
concentrated oxidizer, and an oxidizer/fuel mix is dangerous (as is a
mixture of gasoline and air).  So don't let them mix. :-)

>... The Gemini
>rockets used hypergolic fuels. That way the only ignition system
>required were valves to allow the fuel to mix and spontaneously ignite...

Hypergolics are ahead on simplicity, and the spontaneous ignition makes
really large explosions impossible, because the fuel and oxidizer can't
pre-mix.  (This is why Gemini could use ejection seats, where Mercury
and Apollo needed escape towers.)  On the other hand, the hypergolics
are really vile compounds, corrosive and poisonous, and add considerable
handling hazards.
--
"...the i860 is a wonderful source     | Henry Spencer at U of Toronto Zoology
of thesis topics."    --Preston Briggs |  [e-mail]   utzoo!henry

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

Date: 19 Oct 90 17:02:51 GMT
From: swrinde!zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!forsight!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Hiten Update

Forwarded from Yoshiro Yamada
               Astronomy Section
               Yokohama Science Center
---------------------------------------------------------------
According to ISAS, the Hiten spacecraft made its
fifth lunar swingby on 02-Oct-90 at 12:01 JST (=UTC + 9hrs) at a
selenocentric distance of 22,400 km.  The sixth swingby is expected on
03-Jan-91.

      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

End of SPACE Digest V12 #472
*******************