Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_6/V12_682.TXT

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Date: Fri, 28 Dec 1990 02:15:43 -0500 (EST)
Subject: SPACE Digest V12 #682

SPACE Digest                                     Volume 12 : Issue 682

Today's Topics:
              Usenet equivalent
           Re: Galileo Update #2 - 12/07/90
               Re: Interstellar travel
               Re: Black Holes
           Re: space news from Nov 5 AW&ST
              Magellan Update - 12/12/90
             Re: A human being in vacuum
             Re: A human being in vacuum
            Re: Galileo Update - 12/11/90
               Re: 10th planet?
              Galileo Update - 12/10/90
    Astronaut Springer retires from NASA, Marine Corps (Forwarded)

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: Thu 13 Dec 90 08:45:46-PST
From: Judy Anderson <[e-mail]>
Subject: Usenet equivalent

Is there a usenet equivalent for the space digest?  If so, under what
newsgroup name should I look?  Thanks.
                    Judy Anderson
-------

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

Date: 13 Dec 90 17:00:35 GMT
From: timbuk!sequoia![e-mail]  (Greg Titus)
Subject: Re: Galileo Update #2 - 12/07/90

In article <[e-mail]> [e-mail] (Tim McDaniel) writes:
>In article <[e-mail]>
>[e-mail] (Ron Baalke) writes:
>> A NO-OP command was sent on November 30 to reset the Command Loss
>> Timer to 96 hours.
>
>It's not really a NO-OP then, is it?  A NO-OP with side effects.  Gak.

Every time the spacecraft receives a message from Earth, the Command
Loss Timer (CLT) is set to its timeout value and begins ticking.
(Presumably there is some command which sets this timeout value.)
If the CLT ever ticks down to zero, the spacecraft assumes that
contact with Earth has been lost, and starts looking for it.

The NO-OP is really a NO-OP.  It doesn't do anything.  The mere fact
of its reception is what resets the CLT.  This is not a side effect
of the NO-OP, though.  All commands received by the spacecraft reset
the CLT.

Somebody (Ron?) please tell me if my explanation is incorrect.

greg
--
--------------------------------------------------------------
Greg Titus ([e-mail])             Compiler Group (Ada)
Cray Research, Inc.                               Santa Fe, NM
Opinions expressed herein (such as they are) are purely my own.

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

Date: 13 Dec 90 18:29:14 GMT
From: van-bc!ubc-cs!news-server.csri.toronto.edu!cs.utexas.edu!hellgate.utah.edu!caen!uakari.primate.wisc.edu!aplcen!sun4![e-mail]  (James W. Meritt)
Subject: Re: Interstellar travel

In article <[e-mail]> [e-mail] (Tony Hamilton, WF1-81, x48142) writes:
}Could anyone tell me what the latest designs are for interstellar starships?

There are a few.  Their names start with "V"...

Unless, of course, you mean one for people...


Opinions expressed are solely those of the author, and do not necessarily
represent those opinions of this or any other organization.  The facts,
however, simply are and do not "belong" to anyone.
    [e-mail] or [e-mail] or meritt%aplvm.BITNET

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

Date: 12 Dec 90 19:50:33 GMT
From: sdd.hp.com!news.cs.indiana.edu!maytag!watmath!watdragon!watyew![e-mail]  (Brian or James)
Subject: Re: Black Holes


    Forgive me if I've brought this up here before; I can't recall
if the previous times I've raised this question were all email.

    Shouldn't relativistic effects prevent an outside observer
from seeing the collapsar form? I can see observing a 'really-quite-close-
to-being-a-collapsar object, but do we ever actually 'see' the event
horizon 'form' or does the collapse appear to an outside observer to
take an infinite amount of time?

                        James Nicoll

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

Date: 12 Dec 90 20:51:10 GMT
From: csus.edu!wuarchive!zaphod.mps.ohio-state.edu!van-bc!ubc-cs!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: space news from Nov 5 AW&ST

In article <[e-mail]> [e-mail] (Nick Szabo) writes:
>A major weakness of SSI, Amroc, and other stalling private space companies
>is
>* they are 1-product companies
>* their designs are not compatable with current satellites, but they
>  do not have the resources to develop their own satellites
> ...

Actually, I would say the fundamental problem is that a concentration on
small launchers -- in my opinion a wise decision -- implies that you must
build a market, rather than expecting customers to beat a path to your
door immediately.  The survivors will be those who have the backing to
be patient and help the customers figure out what they want.

Actually, much the same comments apply to any attempt to take the large-
launcher market by storm.  The existing market is small -- if anything
there is overcapacity on the horizon -- and is much more sensitive to
established reliability than to cost.  A new low-cost launcher would,
again, have to *build* a market rather than relying on capturing much
of the existing one.

(The reason I think it wise to stick to small launchers is that all the
problems get bigger with the launcher, including the size of the financial
resources needed for market building.)

>* Build a rocket with a payload fairing exactly the size of Ariane
>  or Delta (so that currently building satellites can be launched)

Ha ha ha.  Nick, are you under the impression that the interfaces to
current launchers are standardized?  Not so.  The size of the payload
fairing is the least of the problems.
--
"The average pointer, statistically,    |Henry Spencer at U of Toronto Zoology
points somewhere in X." -Hugh Redelmeier| [e-mail]   utzoo!henry

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

Date: 13 Dec 90 00:06:58 GMT
From: snorkelwacker.mit.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan Update - 12/12/90


                        MAGELLAN STATUS REPORT
                          December 12, 1990

     The Magellan spacecraft is in good health and performing nominally.  All
seven STARCALS (star calibrations) since yesterday were successful with
attitude updates averaging less than 0.01 degree.

     The M0346 mapping command sequence and its associated parameter files was
sent to the spacecraft yesterday and is now executing.  This 4-day sequence
provides a transition to the Occulted Mapping phase of the mission which
extends from December 14 until January 28.  During this period Venus is
between the spacecraft's antenna and Earth for part of each orbit during the
downlink time.  As a result, part of the mapping of each orbit will be missed.
This period was included in pre-launch planning.  During this period, mapping
sequences will be sent to the spacecraft on Fridays.

     The radar sensor continues its excellent performance, but analysis of the
radar data from orbits #1009 and 1010 verify that tape recorder tracks A1 and
A3 are exhibiting an exponential rate of deterioration.  A technical
discussion of the tape recorder problem between engineers from JPL,
Martin-Marietta, and Odetics is scheduled for tomorrow.

     Twelve new full-resolution image swaths were produced, including one
using an engineering version of the SAR (Synthetic Aperture Radar) processing
software.  This version compensates for a defect discovered in the radar data
of orbit #635.  The SAR processor has completed processing of all available
experiment data records.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 13 Dec 90 13:57:04 GMT
From: csus.edu!wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!cunews!mitel!testeng2![e-mail]  (Chris Stanfield)
Subject: Re: A human being in vacuum

In article <[e-mail]> [e-mail] (Christopher Neufeld) writes:
>   I'd be curious to know what is the rate of heat loss which a human
>body experiences in 15 degree water or zero degree air, both of which
>are surviveable with no special equipment, if not particularly
>comfortable.
Survivable, yes, but for how long? Obviously, time is a very important
fctor in these calculations, as heat loss cannot be instantaneous,
however large the delta t may be.

Chris Stanfield, Mitel Corporation: E-mail to:- uunet!mitel!testeng1!stanfiel
[phone] Ext.4960
We do not inherit the world from our parents - we borrow it from our children.

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

Date: 14 Dec 90 00:11:39 GMT
From: swrinde!cs.utexas.edu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!physics.utoronto.ca![e-mail]  (Christopher Neufeld)
Subject: Re: A human being in vacuum

In article <[e-mail]> [e-mail] () writes:
>In article <[e-mail]> [e-mail] (Christopher Neufeld) writes:
>>   I'd be curious to know what is the rate of heat loss which a human
>>body experiences in 15 degree water or zero degree air, both of which
>>are surviveable with no special equipment, if not particularly
>>comfortable.
>Survivable, yes, but for how long? Obviously, time is a very important
>fctor in these calculations, as heat loss cannot be instantaneous,
>however large the delta t may be.
>
   In the context of this discussion heat loss will only be important if
it kills you in less than about fifteen minutes, and that's really
pushing it. By then, anoxia is likely to have started you inexorably on
the way to maximum entropy.
   I'm sure that people could survive for fifteen minutes in the
environments I mentioned. I'd just like to know what the rate of heat
loss is in those conditions. A human in vacuum, shaded from warm
objects, would radiate about 500 watts.

>Chris Stanfield, Mitel Corporation: E-mail to:- uunet!mitel!testeng1!stanfiel


--
 Christopher Neufeld....Just a graduate student  |
 [e-mail]    Ad astra! |  S = k log W
 cneufeld@{pnet91,pro-micol}.cts.com             |    Boltzmann's epitaph
 "Don't edit reality for the sake of simplicity" |

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

Date: 12 Dec 90 15:37:50 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars![e-mail]  (Ron Baalke)
Subject: Re: Galileo Update - 12/11/90

In article <[e-mail]> [e-mail] (Robert W Murphree) writes:
>Dear Ron Baalke or someone else in the know::i:
>   i
>Has the high gain radio communication antenae deployed properly and is it in good good shape?  Some of us have been waiting a year to see if it has.  The mission depends on a high data rate for real time transmission of video data from 5 AUPlease send me

The High Gain Antenna will be unfurled in May 1991.  The HGA is furled up
to begin with because it wasn't designed to withstand the thermal conditions
when fully deployed within 1 AU of the Sun.  When the VEEGA trajectory was
developed, the spacecraft had to have additional thermal protection, which
included the HGA to be furled up until Galileo is permanently beyond the 1 AU
boundary.  After the Earth gravity assist last Saturday, Galileo has dipped
slightly inside the Earth's orbit, so is still within 1 AU of the Sun.  It
will cross the orbit on Earth on February 16, 1991, and from then on will
be at least 1 AU from the Sun for the remainder of its mission.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 12 Dec 90 17:52:03 GMT
From: magnus.ircc.ohio-state.edu!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!sdd.hp.com!wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: 10th planet?

In article <[e-mail]> [e-mail] (Richard S. Brice) writes:
>> ... already put tight bounds on it, however:  it has to be small, a long
>> way out, well away from the ecliptic, or some combination.
>
>Are their strong reasons for believing that planets could not have
>been formed (or captured) in orbits well away from the ecliptic?

What is known of the mechanism by which the planets formed suggests a strong
bias toward the ecliptic.  The best modern analogy to conditions then --
admittedly not a terribly good one -- is Saturn's rings.  They are about as
close to being two-dimensional as anything you've ever seen, hundreds of
thousands of kilometers across and at most *tens of meters* thick.  (Think
of an absolutely flat disk of thin paper the diameter of a small city.)
Collisions in such a swarm of objects have a very strong tendency to kill
out-of-plane motions.

It is not out of the question, but it would be surprising to find a large
object in such an orbit.  Small ones are no problem -- lots of comets have
severely out-of-ecliptic orbits -- but big ones would have to form by
accretion in a cloud.

>If not, are there good ways of searching for such planets that are both
>far out and well away from the ecliptic?

There are no terribly good ways of searching for planets that are far out,
regardless of the ecliptic.  Assuming an orbit near the ecliptic just cuts
down the search area somewhat.  (On the other hand, it begs the question
of why your Planet X wasn't found by Tombaugh's marathon near-ecliptic
sky search, which was sensitive enough to find Pluto, a minute iceball
hardly worth being called a planet.)

Precision long-term tracking of some seriously out-of-ecliptic probes
might help cut down the odds a lot.  However, the Pioneers and Voyagers
are the last solar-system-escape missions planned for a long time.  All
the near-term planning for outer-planets missions is for orbiters, not
flybys.
--
"The average pointer, statistically,    |Henry Spencer at U of Toronto Zoology
points somewhere in X." -Hugh Redelmeier| [e-mail]   utzoo!henry

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

Date: 13 Dec 90 00:05:30 GMT
From: snorkelwacker.mit.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Galileo Update - 12/10/90


                      GALILEO STATUS REPORT
                        December 10, 1990

     The Galileo spacecraft superbly completed its Earth 1 qravity assist on
December 8.  Earth closest approach altitude was within 7 km of prediction;
closest approach time was within 0.4 second of prediction.

     Galileo continues to collect valuable science data as part of the Earth
Encounter sequence.  At present about 1800 images have been taken with
approximately 1700 more to be taken in the next few days.  The spacecraft's
operating state was successfully reconfigured back to a near cruise mode state
following the Earth flyby.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 12 Dec 90 21:12:32 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Astronaut Springer retires from NASA, Marine Corps (Forwarded)

Mark Hess/Ed Campion
Headquarters, Washington, D.C.                  December 12, 1990
(Phone:  [phone])

Barbara Schwartz
Johnson Space Center, Houston
(Phone:  [phone])


RELEASE:  90-159

ASTRONAUT SPRINGER RETIRES FROM NASA, MARINE CORPS


     Col. Robert C. Springer, selected as an astronaut in 1980
and a mission specialist on two Space Shuttle flights, has
retired from NASA and the U.S. Marine Corps.

     During his first space flight, STS-29 in March 1989,
Springer and his crewmates deployed a NASA Tracking and Data
Relay Satellite and performed numerous secondary experiments,
including a Space Station "heat pipe" radiator experiment, two
student experiments, a protein crystal growth experiment and a
chromosome and plant cell division experiment.  Additionally, the
crew took more than 4,000 photographs of the Earth using several
types of cameras, including the IMAX 70-mm movie camera.

      Springer also flew on STS-38, a Department of Defense
flight, which was launched on Nov. 15, 1990.

     Springer's technical assignments have included serving as a
member of the support crew for STS-3, concept development studies
for the Space Operations Center and the coordination of various
aspects of the final development of the Remote Manipulator System
for operational use.  He also worked in the Mission Control
Center, Johnson Space Center, as spacecraft communicator for
seven flights in 1984 and 1985.

     Springer announced he will work for Boeing Aerospace and
Electronics Division in Huntsville, Ala., as the manager of the
Space Station Freedom's element integration.

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

End of SPACE Digest V12 #682
*******************