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Subject: SPACE Digest V10 #444

SPACE Digest                                     Volume 10 : Issue 444

Today's Topics:
              Re: JPL Microbots
    British Interplanetary Society (was Re: JPL Microbots)
              Magellan Update - 01/17/90
               Re: Edwards AFB
            Re: booster pollution
                JPL Microbots
            Re: booster pollution
              Cosmic Dark Matter
               Re: NASA Funding
              Galileo Update - 01/17/90
             Re: Airlocks & Life support
----------------------------------------------------------------------

Date: 18 Jan 90 15:47:53 GMT
From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Kieran A. Carroll)
Subject: Re: JPL Microbots

> [e-mail] (Brian Yamauchi) writes:
>
>         I remember reading that JPL was investigating the use of
> microbots as planetary rovers (perhaps in conjuction with Rodney
> Brooks' research group at MIT?).
>
>         Does anyone have the names of the people involved or a
> reference to any publications describing this work?


As it happens, yes I do. See

Jones, Ross M.; "Think Small - In Large Numbers";
Aerospace America; October 19, 1989; pp. 14-17

for an article on several types of microspacecraft, including
ones designed at JPL. And, if you're luucky enough to have access
to the Journal of the British Interplanetary Society, see the October
1989 issue. It's a special "Small Mission Systems" issue, and contains
9 articles on microrobots and microspacecraft (award for the most
amusing title goes to Rodney Brooks and Anita Flynn, for "Fast, Cheap
and Out of Control: A Robot Invasion of the Solar System" in this
issue, about the microrobots developed at MIT's AI Lab).

--

     Kieran A. Carroll @ U of Toronto Aerospace Institute
     uunet!attcan!utzoo!kcarroll [e-mail]

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

Date: 18 Jan 90 21:12:02 GMT
From: zaphod.mps.ohio-state.edu!sunybcs!uhura.cc.rochester.edu!rochester![e-mail]  (Brian Yamauchi)
Subject: British Interplanetary Society (was Re: JPL Microbots)

In article <[e-mail]> [e-mail] (Kieran A. Carroll) writes:
>
>And, if you're luucky enough to have access
>to the Journal of the British Interplanetary Society, see the October
>1989 issue. It's a special "Small Mission Systems" issue, and contains
>9 articles on microrobots and microspacecraft (award for the most
>amusing title goes to Rodney Brooks and Anita Flynn, for "Fast, Cheap
>and Out of Control: A Robot Invasion of the Solar System" in this
>issue, about the microrobots developed at MIT's AI Lab).

Is there an address for the British Interplanetary Society from which
I could order back issues (specifically, *this* back issue)?

                Thanks,

_______________________________________________________________________________

Brian Yamauchi                University of Rochester
[e-mail]        Computer Science Department
_______________________________________________________________________________

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

Date: 18 Jan 90 18:51:59 GMT
From: zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan Update - 01/17/90



                     MAGELLAN STATUS REPORT
                          Jan. 17, 1990

     Today, the Magellan spacecraft is 113,471,037 miles from
Earth, traveling at a speed of 63,409 miles per hour relative to
the sun. One way light time is 10 minutes and 12 seconds.

     The spacecraft has been successfully switched back to its
primary command data system computer, and to the high-gain
antenna. The data rate is again at 1,200 bits per second. Earlier
this month the spacecraft detected an error in its memory and
went into a safing mode. It switched to its backup CDS computer
and the telemetry link was switched from the high gain to the
medium gain antenna and the rate was reduced from 1,200 bits per
second to 40 bps.

     Also, the command link was switched from the high gain to
the low gain and the rate was reduced from 62.5 bps to 7.8 bps.

     On January 12, the spacecraft went into fault protection mode
due to a wrong command to the spacecraft from the spacecraft team.
After performing a sweep at 300Hz with a tuning rate of 5Hz/sec,
two way communications was once again established.

     A momentum wheel desaturation was done once daily via non-
standard commands to the spacecraft.

     Magellan operations team members said Magellan is back on
schedule for the start of Cruise-17 command sequence


 Ron Baalke                       |    [e-mail]
 Jet Propulsion Lab  M/S 301-355  |    [e-mail]
 4800 Oak Grove Dr.               |
 Pasadena, CA 91109               |

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

Date: 18 Jan 90 16:35:58 GMT
From: skipper![e-mail]  (Steve Belle)
Subject: Re: Edwards AFB

In article <[e-mail]>, [e-mail] (atkins, robert m) writes:
> I will be out in the area of Edwards AFB later this month. Are there any
> visitor facilities or public exhibits there that would make a detour
> worthwhile? Thanks in advance for any replies.
>
>                                    Bob Atkins
>                                    att!mhuxo!rma


  NASA's Dryden Flight Research Facility has a public tour twice a day, Monday
  through Friday, except for holidays and the week preceding a shuttle
  landing.  The tour includes a film that describes the various flight research
  projects that have been done here (about 30 min) and a tour of the main
  hangar that houses the current research vehicles (about 30-40 min). After
  the tour, you are free to check out the gift shop which also contains
  several exhibits about NASA's flight research history.



  Steve
  [e-mail]

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

Date: 18 Jan 90 16:26:42 GMT
From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: booster pollution

In article <0Zgv2xK00XcS4==[e-mail]> [e-mail] (Daniel Alexander Davis) writes:
>Also, I heard someone mention a local problem
>of heat pollution adversely affecting the ecology
>of Cape Canaveral...

Sounds very implausible.  A shuttle launch is maybe 20-30 gigawatts of power
for half a minute or so (it climbs quickly, remember).  Sunlight is roughly
a gigawatt per square kilometer, continuously.  Any effects from launches
would be transient and localized.
--
1972: Saturn V #15 flight-ready|     Henry Spencer at U of Toronto Zoology
1990: birds nesting in engines | uunet!attcan!utzoo!henry [e-mail]

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

Date: 17 Jan 90 21:58:20 GMT
From: rochester![e-mail]  (Brian Yamauchi)
Subject: JPL Microbots


    I remember reading that JPL was investigating the use of
microbots as planetary rovers (perhaps in conjuction with Rodney
Brooks' research group at MIT?).

    Does anyone have the names of the people involved or a
reference to any publications describing this work?

                Thanks,

_______________________________________________________________________________

Brian Yamauchi                University of Rochester
[e-mail]        Computer Science Department
_______________________________________________________________________________

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

Date: 18 Jan 90 00:23:06 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Re: booster pollution

In article <[e-mail]> [e-mail] (Kim Flowers) writes:

>Hey, what about all those HOH molecules them hydrogen-oxygen boosters
>are spreading all over the place!  Could be a real problem... :)

Actually, they could be, if the launch rate is high enough (read:
much larger than now).  The upper stratosphere is extremely dry.
If we inject water there, it could form high altitude ice clouds,
especially in polar regions.  Such clouds cause net warming by
reflecting infrared radiation.  Also, ice clouds in the Antarctic
stratosphere are thought to play a part in the formation of
the ozone hole.

    Paul F. Dietz
    [e-mail]

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

Date: 17 Jan 90 17:29:31 GMT
From: frooz![e-mail]  (Steve Willner, OIR)
Subject: Cosmic Dark Matter

From article <[e-mail]>, by [e-mail] (Tim Maroney):
> So many scientists seem to take the dark matter for granted,

I'n not sure this is true, but press reports may make it seem so.

> but I've yet to see any clear reason for
> postulating it other than a sort of religious dogma that the universe
> will eventually recollapse.  Is there really any stronger basis for
> believing that we only see ten percent of the universe, or are people
> letting their aesthetics guide their modeling?

There are actually two separate questions that are often confused.  The
first is best called the "Hidden Mass Problem."  Gravitational
evidence, including rotation curves, the stability of spiral galaxy
disks, and the dynamics of clusters of galaxies imply that galaxies
have about 3-10 times more mass than estimated for the visible stellar
population.  The "hidden mass" is distributed in roughly the same way
as the visible mass; i.e., it accompanies the observed galaxies.  The
debate now is over the form of this matter, not its existence.
Possibilities include "brown dwarfs" or almost anything else (black
holes, "planets") in the mass range between 0.05 and 0.005 solar mass.
There are other possibilities as well.

The second problem is usually called the "Missing Mass Problem."  Even
accounting for the hidden mass, observable galaxies add up to only
0.3 or less of the "critical mass," i.e., the maximum mass allowed
where the Universe expands forever (not recollapses).  As far as I can
tell, there is indeed no observational evidence for existence of the
"missing mass;" indeed, there is considerable evidence that the
"missing" mass, if it exists, cannot be in the form of baryons.  The
"missing mass" must also _not_ accompany the visible galaxies but rather
must be more uniformly distributed through the Universe.

Theorists often (always?) "let their aesthetics guide their modeling."
What's wrong with that?  The relevant questions are whether models are
ruled out by existing data and whether simpler models would explain the
data just as well.  The answer to the first is "maybe" and to the second
"no".  Models with mass lower than critical invoke either coincidence
or some other component just as arbitrary as non-baryonic dark
matter.  Both the "hidden mass" and the "missing mass" questions are at
the forefront of research these days, which means that nobody knows the
right answers.
-------------------------------------------------------------------------
Steve Willner            Phone [phone]         Bitnet:   willner@cfa
60 Garden St.            FTS:      830-7123           UUCP:   willner@cfa
Cambridge, MA 02138 USA                 Internet: [e-mail]

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

Date: 19 Jan 90 03:38:27 GMT
From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: NASA Funding

In article <[e-mail]> [e-mail] (Amy Antonucci) writes:
>As I understand it, NASA is under the gov't so that anything that NASA may
>get goes to Congress and then Congress decides how much to give back.

Yup.  Some years ago, when the Viking Fund had collected a substantial
amount of money as a show of public support for keeping Viking Lander 1
operational (there was talk of shutting it down), complications arose
when the time came to hand it over.  The government apparently can't
accept donations earmarked for specific projects or groups.  I believe
it was eventually worked out with the Fund contracting with JPL for
Viking data-analysis work, which was desirable in itself and also eased
pressure on the Viking budget a little.  (The political point had been
made anyway.)
--
1972: Saturn V #15 flight-ready|     Henry Spencer at U of Toronto Zoology
1990: birds nesting in engines | uunet!attcan!utzoo!henry [e-mail]

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

Date: 18 Jan 90 18:51:23 GMT
From: zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Galileo Update - 01/17/90



                     GALILEO MISSION STATUS
                        January 17, 1990

     Today the Galileo spacecraft is just under 18 million miles
from Earth, and 8.7 million miles from Venus. Round-trip light
time to the spacecraft is about 3-1/4 minutes. During the next
week or so, there will be an approximate line-up between the Sun,
Venus, Galileo, the Earth and Jupiter. (Jupiter was at opposition
two weeks ago, and the spacecraft is several degrees above the
ecliptic plane.)  Galileo has rolled up 141 million miles around
its orbit, at a velocity which has increased to 75,600 mph, and
with 44 million to go before Venus encounter February 9 at 10
p.m. PST.

     The health of the spacecraft is very good; it is in a
"safed" cruise mode following an incident Monday in which the
attitude control computer invoked system fault protection
because of an incompatibility found while performing a star
calibration with the gyros off.  The flight team analyzed the
incident quickly and are now working to gradually restore
various functions which were halted automatically during the
"safing" response.  The spacecraft is spinning in all spin
mode at 2.89 rpm, and sending telemetry at 1200 bits per second.

     On January 9, Galileo had its first demonstration
of "Delta DOR," a Very Long Baseline Interferometry technique
using two DSN stations simultaneously to produce very precise
angle tracking data.  This will be added to doppler and
ranging to refine spacecraft navigation for the Earth and
Jupiter encounters, to improve targeting while saving
propellant.  The DSN's large antenna in Spain, DSS-63, has
been down for several weeks to replace a bearing.  Repairs
are progressing and the antenna is expected to be operating
in time for Venus encounter.

     Last week the Project determined that no further
trajectory correction is needed for the Venus flyby; there
will be no TCM-3.  Venus encounter and science will be part
of the operating sequence called EV-6, which will be
effective February 5-18.


 Ron Baalke                       |    [e-mail]
 Jet Propulsion Lab  M/S 301-355  |    [e-mail]
 4800 Oak Grove Dr.               |
 Pasadena, CA 91109               |

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

Date: 17 Jan 90 17:01:27 GMT
From: mcsun!ukc!icdoc!syma![e-mail]  (Andy Clews)
Subject: Re: Airlocks & Life support

From article <[e-mail]>, by [e-mail] (Steven_Tenney):
> oops! hit the wrong button, sorry!

A likely WW3 scenario, I fear!  :-) 8-{


--
Andy Clews, Computing Service, Univ. of Sussex, Brighton BN1 9QN, ENGLAND
JANET: [e-mail]   BITNET: [e-mail]
Voice: [phone] ext.2129

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

End of SPACE Digest V10 #444
*******************