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Date: Thu, 23 Mar 89 03:16:51 -0500 (EST)
Subject: SPACE Digest V9 #307

SPACE Digest                                      Volume 9 : Issue 307

Today's Topics:
       Soviet Phobos II in synchronous orbit with Martian moon
           Space station & stone-age units
                Voyager update
         Re: Samara Probe for Remote Imaging
             NASA FY-1990 Budget Numbers
               Re: SPACE Digest V9 #297
               Moronic TV news coverage
            NSS Hotline Update for 3/17/89
----------------------------------------------------------------------

Date: Thu, 23 Mar 89 00:55:38 EST
From: Glenn Chapman <[e-mail]>
To: [e-mail], [e-mail],
        [e-mail]
Subject: Soviet Phobos II in synchronous orbit with Martian moon

     The Soviet's announced on short wave (Mar. 21) that the Phobos II probe
has made another orbit change.  This burn puts the probe in synchronous
orbit with the Martian moon, making it one of the final velocity changes
before the rendezvous.  This position will be maintained for some period
while additional pictures are taken of the surface to determine the
accuracy of this orbit.  All of this suggests that we are probably within
a week or two of the final approach.  However, no statements were made as
to the ejection of the main engine system, which should occur just prior
to rendezvous
     The original plans call this for the probe to move to within 60 Km
(35 mi) of Phobos and stay there with it solar cells orientated so that
the batteries may be fully charged.  Then using hydrogen peroxide
jets the final run will begin with it approaching to about 2 Km (1.25 mi)
of Phobos, maintaining the antenna towards earth.  Using the jets it
will aim to get within 30 to 80 m ( 98 - 260 feet) of the surface
and hover there for about 20 minutes.  The craft at that point
will be moving about 2 - 5 m/sec (7 - 16 ft/sec) horizontally over
the surface with the laser altimeter maintaining the altitude to
avoid major surface highs.  Note, the orbital velocity at the surface
of phobos is about 11 m/sec (37 ft/sec) by my calculations, so the probe
is really not in orbit about Phobos during this rendezvous.  Since
the approximate mean surface gravity of Phobos is 1.6 cm/sec/sec
(0.0016 earth G).  Thus it would take about 2 minutes for the probe to
fall a 100 meters (330 ft) height.  Also this gravity value is
significantly variable over the surface since the moon is not
spherical - 28 x 23 x 20 Km ( 17 x 14 x 12 mi) as measured on
the 3 major axis.  The escape velocity, by the way, is about 16 m/sec
(52 ft/sec).  All of this shows that the jets will be a significant
factor in maintaining that altitude.
   After this period during which the photographs, laser and ion
spectrographic, radar, X-ray etc. (I will post details later)
observations are done the two landers will be release just prior to
the main probe leaving the satellite.  The probe will move off 2 km from
the moon, and maintain contact with the landers.  After this it will move
off to a 9700 Km (6030 mi) orbit to observe the surface. (Phobos II orbital
plans from "Race to Mars" by Miles and Booth).
    We are only days away now from this attempt.

                                                      Glenn Chapman
                                                      MIT Lincoln Lab

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

Date: Fri, 17 Mar 89 10:03:22 EST
From: Marvin Minsky <[e-mail]>
Subject:  Space station & stone-age units
To: [e-mail], [e-mail]
Re: SPACE Digest V9 #296

I encountered one industry that tolerates english and metric units.
We were buying some fabric in Kyoto, for dressmaking.  The stuff was
sold by the meter-yard!  Really.

Reason simple.  When you cut off a length you use the meter-stick for
measure, because Japan is metric.  But the cloth is woven on old
english-type looms which all were 72 inches wide, so the stuff still
comes in two-yard widths.

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

Date: Thu, 16 Mar 89 09:37:41 PST
From: Peter Scott <[e-mail]>
Subject: Voyager update
X-Vms-Mail-To: EXOS%"[e-mail]"

Excerpted without permission from NASA Voyager Bulletin, Mission Status Report
# 85, March 3, 1989 [stuff in square brackets is mine]:

It's not just a fuzzy tennis ball after all...
----------------------------------------------

A bright cloud feature on Neptune, similar to spots seen by planetary
astronomers using Earth-based telescopes, is visible in images taken by
Voyager 2 on January 23, 1989 when the spacecraft was about 309 million
kilometers (185 million miles) from the planet.  The fact that distinct
cloud features are visible while the spacecraft is still so distant suggests
that pictures taken as Voyager 2 approaches its August 1989 flyby of Neptune
will show far more detail than was visible in the atmosphere of Uranus,
which Voyager 2 encountered in January 1986.  (Due to the lack of visible
cloud features, Uranus has been lightheartedly described as a "fuzzy blue
tennis ball," and less kindly as bland.)

The cloud is at about 30 degrees south latitude, and its motion during the
time between images is consistent with the 17- to 18-hour rotation period
derived from observations with Earth-based telescopes.  The January images
show details as small as about 6000 kilometers (3500 miles).  The cloud
has not yet been confirmed to be any of the cloud features seen on Neptune
by Drs. Richard Terrile of JPL and Brad Smith of the University of Arizona
at Las Campanas Observatory, Chile, in 1983, or by Dr. Heidi Hammel of JPL
at the University of Hawaii's Mauna Kea facility in 1988.  The features
seen from these Earth-based telescopes were best seen through methane filters
not available on Voyager 2, and imaging scientists have been somewhat concerned
that such features might not be visible to Voyager 2's cameras.

The mottled appearance of Neptune in these frames is likely to be "noise"
in the camera system.  Color versions of these images, assembled from pictures
taken through violet, clear, and orange filters, show a dark band of clouds
encircling the planet's southern pole.  [...]  The natural color of Neptune
is a pale blue-green, caused by the absorption of red light by methane gas
in the planet's atmosphere.

[...] Spacecraft review
      -----------------

[...] At launch, each spacecraft carried about 105 kilograms (232 pounds)
of hydrazine.  During its 11.5 years in space, Voyager 2 has used about
60 kilograms (140 pounds) of hydrazine.

[...] Each Voyager is powered by three radioisotopic thermoelectric generators
(RTGs), which produce electrical energy throutgh the conversion of heat
generated by the radioactive decay of plutonium-238.  At launch, the power
output of the RTGs was about 423 watts.  The power output steadily declines
as the plutonium decays, and is now about 380 watts.  The science instruments
require about 105 watts, or about the same wattage as a typical light bulb.

[...]  Instrument Description and Health
       ---------------------------------

[...] Each Voyager spacecraft carries two imaging cameras: a 200-mm,
f/3.5 wide-angle camera using a refracting telescope and a 1500-mm f/8.5
narrow-angle (telephoto) camera using a reflecting telescope.  Each camera
carries a one-inch selenium-sulfur vidicon to convert an optical scene into
electrical signals.

Each frame consists of 640,000 pixels, each of which is expressed as a level
of gray on a scale from 0 (black) to 255 (white).  [...]  The sensitivity
of the filters ranges from 3460 (ultraviolet) to 6184 angstroms (red-orange).
[...]

Voyager 2's narrow-angle camera has dust specks on the vidicon which result
in faint, doughnut-shaped blemishes in images [what do they expect, it's
been twelve years since the maid came].  In addition, the emission of the
vidicon cathode in the narrow-angle camera has decreased since launch.

[...]  The photopolarimeter measures the way light is scattered from particles
in an atmosphere or on a surface.  By studying the polarization of reflected
light as ther lighting geometry changes during a flyby, scientists can make
inferences about the nature of a planetary surface or atmosphere.  The
photopolarimeter can also be used to study rings by measuring the intensity
of a background star as the starlight passes through the rings.

The photopolarimeter consists of a 200-mm Cassegrain telescope with filters,
polarization analyzers, and a photomultiplier tube to convert incoming light
into electronic signals.  It covers three wavelengths in the region between
265 and 750 millimicrons.  Five of the eight original filters and four of
the eight original analyzers are no longer accessible.  [...]

Voyager 2's Health
------------------

Both Voyagers have experienced several health problems since launch, some
minor and some rather major ones.  Nevertheless, mission controllers have
in every case been able to identify the problems and provide a way to continue
to meet mission objectives.

In September 1977, about a month after launch, Voyager 2 suffered a hardware
failure in the FDS [flight data subsystem - one of the computers].  As a
result, 15 engineering measurements can no longer be made (about 215
engineering measurements remain).

In 1978, eight months after launch, Voyager 2's main radio receiver failed,
and a tracking loop capacitor failed in the backup receiver.  As a result,
Voyager 2 can receive signals in only a narrow "window" of frequencies--and
the window slides.  The window is about 1000 times narrower than it originally
was, and temperature changes in the radio receiver of even 1/4 degree cause
the window to slide up or down in frequency.  Temperature changes can be
caused by heat generated by the spacecraft's electronics.  The flight team
has devised a rigorous routine for commanding the spacecraft.  Signals are
sent several times at different frequencies to determine the receiver's
current frequency "window".  Commands are then transmitted, after calculating
where the receiver's "window" will be, and taking into account how the signal
frequency will change due to the Earth's rotation and other motions.

[...]  In August 1981, just after Voyager 2 passed Saturn, the scan platform
quit moving.  Three years of intensive analysis and testing of similar parts
on Earth, and of the scan platform on Voyager 1, led to a failure model
and to guidelines for safe usage of the platform.  The failure has been
attributed to a lack of full lubrication of the bearing area between the gear
and pin in the azimuth actuator.  Lubricant has probably migrated back to
the bearing surfaces, healing the problem.  Adherence to the guidelines
for safe usage permitted Voyager to complete a successful encounter with
Uranus in 1986, returning some of the highest resolution images ever taken
of solar system bodies.  [...]

Just days before its closest approach to Uranus, Voyager 2 suffered the
loss of one word of memory in one FDS processor.  As a result, bright and
dark streaks appeared in images.  Only imaging data was affected, and a
software patch was sent to bypass the failed bit.

Despite a little arthritis, a little hearing problem, and some loss of memory,
Voyager 2 is still in excellent operating condition, and gaining rapidly
on Neptune and Triton.

Peter Scott ([e-mail])

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

Date: 17 Mar 89 18:40:55 GMT
From: rochester!uhura.cc.rochester.edu![e-mail]  (Peter Owings)
Subject: Re: Samara Probe for Remote Imaging

In article <10900004@tippy> [e-mail] writes:
>
>Reprinted from "NASA Tech Briefs," February, 1989.
>
>"This conceptual device would scan automatically, without costly aiming
> or stablizing devices."
>
>   - NASA's Jet Propulsion Laboratory, Pasadena, California


    I would think the most costly part of this device would be
the detectors.  Is there a plan to try to recover them before they
spiral into the Earth's/planet's surface?  Otherwise I would think
it fairly costly  to drop these detectors only to have them smashed
on some planet.

    Peter Owings            [e-mail]
    University of Rochester, Department of Physics and Astronomy

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

Date: 17 Mar 89 19:43:40 GMT
From: vsi1!wyse!mips!prls!philabs!ttidca![e-mail]  ( Avatar)
Subject: NASA FY-1990 Budget Numbers

In article <[e-mail]> [e-mail] (William Baxter) writes:
>>Here is the NASA budget request for fiscal year 1990 (beginning
>>October 1, 1989).
>>             NASA FY 1990 BUDGET SUMMARY
>>            (Millions of Dollars)
>>Shuttle Production & Capability Development  1128.2     1305.3 (total)
>>Space Shuttle Operations                     2305.2     2562.7 (total)
>
>>Expendable Launch Vehicles                     85.5      169.5
>
>Is it any wonder that the dream is dead at NASA?
>William Baxter

 This is an astute point, but what I wonder is how much of each of these
numbers is the cost of management vs. tech support/hardware??

 Does anyone have access to the information ???

 Would they be willing to post it??

 ...why NOT?

 Maybe I could write some letters...

-Avatar-> (aka: Erik K. Sorgatz) KB6LUY           +-------------------------+

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

Date:         Fri, 17 Mar 89 12:29:46 EDT
From: "ERIC E. WALLIS" <[e-mail]>
Subject:      Re: SPACE Digest V9 #297

Speaking of buying Soviet satelite photographs... when are we going to
get a look at their photos from Mars?

=========================================================================
347DODT @ CMUVM.BITNET  * " May fortune favor   * " Houston, we have
ERIC E. WALLIS          *   the foolish...      * a negative on that
NO MORE BURRITOS!!!!!   * -- Admiral James T.   * orbit trajectory..."
CENTRAL MICH UNIV       *    Kirk ( NCC- 1701)  * --- Calvin and Hobbes
=========================================================================

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

Date:         Fri, 17 Mar 89 10:36:05 EDT
From: Bill Sallee <[e-mail]>
Subject:      Moronic TV news coverage

The network coverage now doesn't seem to be as bad as it was in the
1960s.  Most of those guys came from radio and were incessant talkers.
I think anyone who strangled them on the air would have been let go by
any jury.  I've never heard of CSPAN-II (Lexington, KY) but we do have
CSPAN.  I never thought to check that channel at launch time.  Commercial
free coverage would be a real bonus also.

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

Date: 19 Mar 89 17:46:00 GMT
From: arisia!cdp![e-mail]
Subject: NSS Hotline Update for 3/17/89


This is the National Space Society's Space Hotline for the week ending
March 17, 1989.

With the closing of the STS-29 mission, the crew of the Space Shuttle
Discovery are ending their mission by stowing gear and wrapping up
experiments.  The landing is scheduled for 9:32am EST Saturday morning at
Edwards Air Force Base in Calif.  A turnout of 20,000 spectators is
expected to watch Discovery land.

Friday morning President Bush called the crew to congratulate them on a
successful mission which was the first of his new administration.  In the
conversation he stated that the space program, especially the space station
is an investment in our future.  He went on to say that even though we are
living through difficult budgetary times he is determined to go forward
with a strong, active space program.

The mission so far has been one of qualified success. Successes included
the deployment of $100 million Tracking Data Relay Satellite, protein
crystal growth experiments, and various other life sciences experiments.
Problems arose as the false readings in the hydrogen storage tank number 3,
a broken IMAX movie camera belt, and the fluid ammonia heat exchange
experiment. All remedied eventually, but they did cause headaches for the
crew.

The first generation heat exchange system designed to be used on the space
station did not work as planned due to air bubbles that kept the ammonia
fluid from radiating heat into space.  Firing the motors of Discovery did
not free the air bubbles in the 50 foot pipe, so the crew will flush the
pipe and give it one more try prior to landing.  Using the IMAX camera the
crew filmed environmentally sensitive areas of the earth including a huge
smoke cloud over the Amazon, and the Sahara Desert.

Meanwhile back at Kennedy Space Center.....
NASA officials stated that preparations for the launch of the Space Shuttle
Atlantis and its Magellan Venus Radar Mapping probe are right on the mark
for launch on April 28, 1989.  The launch is time critical since the window
for the Magellan spacecraft lasts only until May 25th.  The Magellan Radar
Mapper will map about 90% of the planet's surface after making its 26
million mile journey to the cloudy planet.

Tennesse's Democratic Senator Al Gore told NASA officials that they must
come up will better budgetary justification for the space station if the
rest of the Senate is to approve the $2.1 billion needed for the program.
The Senate Science, Technology and Space subcommittee Chairman asked them
to provide justification in terms of foreign policy and technological
justifications.  Other Senators wanted to know how the program benefits the
every day individual living in places such as New York City or the
Mississippi Delta.

NASA space station chief James Odom responded by asking the Senate to
approve the 22% NASA budget increase because any significant cut would kill
the space station program.  In addition he stated that an action such as
that would be irresponsible due to the fact that we've made so many
commitments and agreements with foreign partners.

NASA Administrator Dr. James Fletcher and the Japanese Ambassador to the US
signed a memorandum of understanding which spells out the details of
cooperation on development of the space station.  The Japanese will
contribute to the station by providing a permanent experimentation module
in which materials processing and life sciences experiments will be
conducted.

Science writer Carl Sagan in testimony to the House Space Sciences and
Applications Subcommittee last week stated that the Moon is a dead end and
that Mars should be the next target of exploration for NASA.  He went on to
state that the Moon is not a stopping point between the space station and
Mars and is a waste of time and resources.  A manned mission to Mars would
cost about $60 to $100 billion dollars spread out over 20 years.

Meanwhile back at the Commerce Dept. officials there have been busy
rescinding their orders given last week to turn off Landsats 4 & 5.
Operation of the satellites will continue while the White House reviews the
matter further. California Democratic Representative George Brown, Jr.
initiated a letter signed by 103 other members of Congress addressed to
President Bush and Vice President Quayle asking them to make sure that the
$9.4 million is found to keep the satellites running till the end of the
fiscal year.

JPL scientists have discovered several unknown active fault lines in the
Mojave Desert in CA.  The discovery was made from data obtained by the
Thematic Mapper instrument aboard Landsat 5.

The Soviet space probe Phobos, which is in orbit about Mars, is drawing
closer to its destination the moon Phobos.  On April 1 the spacecraft will
pass within 150 feet of the lopsided moon and deploy two landers.  One
lander will harpoon itself into the surface while the other hops around on
the surface.

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

End of SPACE Digest V9 #307
*******************