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Subject: SPACE Digest V12 #681

SPACE Digest                                     Volume 12 : Issue 681

Today's Topics:
              Galileo Update - 12/12/90
             space news from Nov 19 AW&ST
              Voyager Update - 12/13/90
     UNDERSTANDING SOLAR TERRESTRIAL REPORTS - DOCUMENT CONTENTS

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription notices,
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Date: 13 Dec 90 00:08:18 GMT
From: snorkelwacker.mit.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Galileo Update - 12/12/90


                       GALILEO STATUS REPORT
                         December 12, 1990

     The Galileo spacecraft completed sending back the images for the Earth
spin movie were earlier today.  All but 22 (10 contiguous in one segment,
12 contiguous in another) of the 1500 images were successfully retrieved.
This loss was expected due to DSS (Deep Space Station) view period
constraints; the loss has a minor effect on the integrity of the spin movie.
Some of the Earth images are being shown on the TV monitors at JPL.

     Galileo, speeding away from Earth, will continue to collect valuable
Earth science data for the next several days.  Tomorrow, in addition to
continued science activities, a SITURN to lead the sun will be performed.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 13 Dec 90 06:24:41 GMT
From: usc!cs.utexas.edu!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: space news from Nov 19 AW&ST

[This is a heavy news week.]

Space station designers trying to decide whether it is more important to
get started on the latest redesign or finish the enormously complex series
of preliminary design reviews on the last design.  NASA favors the latter,
on the grounds that much of it will not need to be re-done.  [Wanna bet?]

X-30 contractor team announces first design cycle should be complete by
February.

Galileo to take a slow-motion movie of Earth after close approach, taking
one frame a minute for a full day to show a full rotation of the Earth in
one minute at standard movie rates.  The next Earth encounter, two years
from now, will include an attempt to get a shot of the Moon and the Earth
together.

Magellan went on strike :-) for 41 minutes Nov 15, but mapping is expected
to resume within a few hours, due to improved spacecraft software and ground
procedures.  There appears to be an occasional random fault in the attitude
control system, which is tentatively blamed for the chaos in August too.

Atlantis launched Nov 15, carrying a 22klb eavesdropping satellite said
to be aimed mostly at the Gulf area.

Titan IV launched Nov 12, carrying a missile-warning satellite for Gulf
surveillance.  Oddly, although the payload is virtually identical to the
warning satellite carried up by the shuttle a while ago, the Titan one
is secret and the shuttle one wasn't.

1991 shuttle manifest announced, 6-7 flights.  STS-39 in Feb-March will
carry the (military) Cirris infrared Earth-observation telescope plus an
infrared-background-survey experiment.  The Gamma Ray Observatory will go
up in April, accompanied by some EVA experiments.  SLS-1 (Spacelab Life
Sciences) will go in May, another TDRS in June, and another missile-
warning satellite in July.  Spacelab J, the Upper Atmosphere Research
Satellite, and the International Materials Lab will fight it out for
the last 1-2 slots.  [Prediction:  Spacelab J, being Japanese, will lose.]

Drawings of a large Soviet design study [note, just a design study, despite
some claims otherwise] for a reusable heavylift booster, using four flyback
strap-on boosters plus a winged core stage whose large nose-mounted payload
fairing would slide back over the body somewhat to give a better shape for
reentry and gliding flight.  All liquid-fuelled, naturally.  The boosters
might be derivatives of the Energia strap-ons, while the core stage would
use three Energia core engines (Energia uses four).

Space Studies Institute [!] signs deal to represent NPO Energia in the
Americas, for sales of Energia and Buran launch services and payloads
aboard Mir.  SSI does not plan any challenge to current US government
objections to flight of US payloads on Soviet boosters.  [Curious; see
next item.]

Space Studies Institute signs letter of intent with NPO Energia for launch
of SSI's privately-funded Lunar Prospector mission [a lunar polar orbiter
carrying a gamma-ray spectrometer].

US and Canadian electric utilities discuss rapid development and launch of
a solar-storm-warning satellite to help protect power-distribution networks
against high solar activity.  The utilities fear possible repetitions
of the 13 March 1989 storm, which plunged Quebec into a nine-hour blackout,
nearly blacked out the entire US Eastern Seaboard as well, and caused
serious malfunctions and significant equipment damage in many areas.
A small satellite would be parked in a halo orbit around the Earth-Sun
L1 point [where ISEE-3 was stationed for some years].  It would be
quite simple, carrying a UCLA magnetometer and an LANL plasma analyzer.
The utilities hope that it could be up by 1992, given rapid commercial
development, launch on Pegasus, and commercial funding throughout.  The
utilities hope that NOAA would contribute some money -- and indeed, both
NOAA and the USAF are interested -- but government budgeting is too slow
for the perceived urgent need.

Senior Soviet officials outline a proposal for a US-USSR Mars mission by
2011, calling for a joint space station for unmanned-probe assembly,
a reusable tug for hardware transport, a living module for crew transport
(built by the USSR), and a manned lander (built by the US), all launched
by improved Energias.

Image of the Caribbean from China's Feng Yun 1B weather satellite, which
apparently uses the same signal format as the US's NOAA/Tiros series.

Feature article on MBB's proposal for a German X-plane, dubbed "Hytex",
as an experimental precursor to the large hypersonic booster for Saenger.
Hytex first flight would be 1998.  It would be slightly larger than the
X-15, powered by kerosene/hydrogen turbo/ramjets, and capable of Mach 5.5.
It is envisioned as a joint European project; Sweden has already joined,
Italy is expected to join soon, and other countries are being courted.
It is considered a necessary preliminary to Saenger because too many key
technologies cannot be tested on the ground.  "We can't do propulsion
integration on the basis of numeric simulation."  Reaching the desired
speed would be easy; the tricky part is making Hytex a reasonably good
simulation of the Saenger first stage.  Originally Hytex was going to
be a two-stage mini-Saenger, "...but the aerodynamicists thought they
could predict the [staging] effects, so the technology demonstrator did
not need to be a two-stage vehicle.".  It will fly from the ground, and
will be manned.  An air launch from an A300 was considered, but it
would have complicated the propulsion design badly.  Testing within
densely-populated Europe was felt to require human pilots, horizontal
takeoff, conventional landing, and no jettisoned parts.  Materials will
be largely conventional for the sake of development schedule.  [And to
think it took the Germans to do this...  This is precisely the sort of
thing NASA could have, and should have, been doing 15 years ago.]

Plans for increasing the number of US imaging spysats, for the sake of
disarmament-treaty monitoring, are on hold due to high cost and debate
about the need.

Inmarsat approves world's first commercial satellite telephone installation,
on a Gulfstream 4 business jet.  [The G4 is one of the high-end business
jets, meant for long-haul work.]  More are expected within weeks, followed
by airliner installations.  (Several have flown experimentally in airliners.)
Racal and Honeywell, together the only supplier, have over 40 orders already.

Hubble repairs will require the most ambitious EVA of any shuttle mission
yet, tentatively three major spacewalks.  The first will replace the solar
arrays in an attempt to cure the persistent jitter problem.  [They were
slated for eventual replacement anyway.]  The second would replace the
Wide Field/Planetary Camera with WFPC2, which will incorporate correcting
mirrors to cope with Hubble's aberrant optics.  [WFPC2 was planned for this
mission anyway, since the WFPC technology has been advancing rapidly.]
The third would be the most interesting part; see 2nd next paragraph.  A
reboost is not likely to be necessary, although one is planned as part
of the second maintenance mission in 1996.  NASA would like to do the
three spacewalks in one flight, despite the demanding schedule, because
of the shortage of shuttle missions and a desire to try out intensive
spacewalk operations in preparation for the space station.

Hubble's solar-array jitter problems actually appear to be a combination
of two separate wobbles, an end-to-end 0.1Hz flexing during sunlight-shadow
transitions, and a 0.6Hz sideways flexing during sunlit periods.  The first
has been dealt with by software, but the second then caused trouble.  It is
possible that a fully adequate software solution may not be feasible, given
the limited computer power available.  ESA (which supplied the arrays) and
NASA are still trying to sort out the exact nature of the problems.

The big question is how to deal with the effect of the aberration on the
four "axial" instruments.  NASA has ruled out anything that might risk
disturbing the major mirrors or contaminating the optics, which are
already returning major results despite the problems.  One possibility
is to just try to deal with the Faint Object Camera and leave the
photometer and spectrographs alone.  ESA will decide on the best approach
to the FOC in January.  Building a new one is probably too expensive, but
in-space alterations are possible.  It would require opening sections that
were never meant for on-site servicing, but it is considered less difficult
than the successful Solar Max repair in 1984.    A more daring possibility
is to remove the photometer entirely and replace it by a module which
would swing correcting optics into the light path going into the other
three axial instruments.  There is already a spare axial-instrument box,
built as a filler in case one of the instruments was not ready for launch
for some reason.  The trick will be making the optics boom sufficiently
adjustable by remote control on a tight development schedule.  [It's a
pity to sacrifice the photometer.  It is the least-used instrument mostly
because it is aimed at exploring a whole new area of observations -- very
rapid light fluctuations -- that is simply inaccessible from the ground,
and consequently is too poorly known to attract lots of observing interest
yet.  Alas, this is nevertheless probably the best thing to do.]

USAF is ahead of schedule on activating the second Titan IV launch pad
at the Cape, set to be used first to launch NASA's Mars Observer in 1992.
The first Titan IV launch from Vandenberg will be next year; that pad
was accepted by the USAF last month.

Letter from Robert J. Naumann of Huntsville:  "As the former project
scientist for the habitat and laboratory modules, I and others in my
working group shared a vision of the space station as a national
microgravity laboratory where, for the first time, we would have the
power, duration, and laboratory resources to carry out microgravity
experiments in an interactive manner..."  He's given up on that due
to the steady shrinkage of power, facilities, and crew time, and
says it's time to push for second best, a man-tended free-flier to
at least give continuous high-quality microgravity.

Letter from Thomas Armstrong of Paramount, Calif, observing that the
X-30 would appear to have a serious control problem in common with the
space shuttle:  its longitudinal control surfaces are too far aft.
The result is that their flap action dominates their elevator action,
so pulling the nose up makes the aircraft sink *faster*, while pushing
it down *reduces* the sink rate.  This happens to some extent on all
delta-wing aircraft, but on draggy unpowered craft like the shuttle
orbiter, it is a major problem.  The landing technique is quite unlike
that used to land a normal aircraft, and it puts quite a strain on the
pilot.  "Add to this an apparent lack of direct forward viewing and
the X-30 may prove to be one cubic handful to manage during final
flare and landing."
--
"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 22:57:28 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Voyager Update - 12/13/90


                        VOYAGER STATUS REPORT
                          December 13, 1990

                              Voyager 1

     The Voyager 1 spacecraft collected routine UVS (Ultraviolet Spectrometer)
data on sources HD206165, HD217675, and HR264.  On December 4, one frame of
high-rate PWS (Plasma Wave) data was recorded.   On December 6, a TLC (Tracking
Loop Capacitor) test was performed from the 70 meter station in Spain, but
there was no downlink station coverage for it.  A Dummy CC command was
transmitted to the spacecraft on December 5 to reset the Command Loss Timer;
receipt of the command was verified.


                              Voyager 2

     The Voyager 2 spacecraft collected routine UVS data on source 3C273.  UVS
data were acceptable except for a short period on December 3, which was noisy.
On December 4 a frame of PWS data was recorded on the DTR (Digital Tape
Recorder) for future playback.  On December 6, the scan platform was slewed to
sky position OV to search for oxygen emissions.

     On December 3 the SFOC (Space Flight Operations Center) PC interface to
the Voyager DACS (Data Capture and Staging) Reed-Soloman decoder was installed;
neither the FOT (Flight Operations Team) nor SCT (Spacecraft Team) was informed
of it's installation or of the use of it to process spacecraft data until the
next day.


               CONSUMABLE STATUS AS OF 12/13/90

    P R O P E L L A N T    S T A T U S           P O W E R

              Consumption
                One Week  Propellant Remaining Output Margin
    Spacecraft     (Gm)               (Kg)      Watts  Watts
     Voyager 1      5             36.2 + 2.0     366   55
     Voyager 2      7             39.3 + 2.0     370   61

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

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

Date:    Thu, 13 Dec 90 21:05:02 MST
From: [e-mail] (Cary Oler)
Subject: UNDERSTANDING SOLAR TERRESTRIAL REPORTS - DOCUMENT CONTENTS
X-St-Vmsmail-To: ST%"[e-mail]"

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

The document "Understanding Solar Terrestrial Reports" has been completed and
is ready for distribution.  It is an extensive document covering a great many
topics.

Due to the enormous number of requests that have been received for this
document, it was decided that the document should first be distributed over
the nets before being sent out directly to those individuals who requested
it.  This will significantly reduce the amount of time and work involved in
distributing the document to those who requested it.  To all those who
requested the document, thanks for being patient.  It is hoped the document
will prove useful and informative.

The document has been divided into two independent parts.  Due to the size
of the document, each part has been divided into several "sections."  All of
the sections have been uuencoded.  To obtain the complete document (both
parts), collect all of the sections which appear over the networks for BOTH
parts and follow the instructions contained in each message.  After
uudecoding both parts, you should have two files "part1.doc" and "part2.doc"
which can then be printed out separately.

This document is printer-ready.  It should be globally compatible with all
printer types.  If any of you have problems printing out the document or
do not obtain all of the sections within a couple of weeks, notify
"[e-mail]" of your problems so they can be worked out.

The table of contents for both parts of the document have been extracted and
reprinted below:


PART I: MORPHOLOGICAL ANALYSIS OF PHENOMENA

   Introduction ....................................................    1
   Characteristics of the Sun ......................................    2
   Sunspots and the Solar Flux .....................................    3
   The Sunspot Cycle ...............................................    6
   The 22 Year Solar Cycle .........................................    6
   The Solar Atmosphere ............................................    7
   The Photosphere .................................................    7
   The Chromosphere and Spicules ...................................    8
   The Corona and Coronal Holes ....................................    9
   Forms of Solar Activity .........................................   10
   Plages and Faculae ..............................................   11
   Prominences and Filaments .......................................   12
   Solar Flares ....................................................   14
   Polar Cap Absorption Events .....................................   16
   Significance of Sweep Frequency Events ..........................   17
   The Slowly Varying Component ....................................   17
   Type I Bursts and Radio Noise Storms ............................   18
   Type III Radio Bursts ...........................................   18
   Type V Radio Burst Emissions ....................................   19
   Type II Radio Bursts ............................................   19
   Continuum Type IV Radio Bursts ..................................   20
   The Earth's Magnetic Field ......................................   21
   Geomagnetic Substorms ...........................................   22
   Geomagnetic Storms ..............................................   23
   Ionospheric Effects of Geomagnetic Storms .......................   24
   Radio Signal Propagation ........................................   25
   Propagation of VLF Signals ......................................   26
   HF Signal Propagation ...........................................   26
   Long-Distance VHF Signal Propagation ............................   29
   Characteristics of Auroral Activity .............................   31
   Auroral Relationship with Geomagnetic Activity ..................   31
   Significance of Aurora's to Astronomers .........................   33
   Auroral Classifications .........................................   33
   The Impacts of Geomagnetic Storms and Solar Activity ............   35
   Magnetic Storm Induction ........................................   36
   Atmospheric Circulation Modifications ...........................   38
   Atmospheric Pressure Responses to Solar Flares ..................   38
   Atmospheric Electrical Enhancements following Major Flares ......   40
   Geomagnetic Effects on Atmospheric Pressure .....................   42
   Concluding Remarks ..............................................   44


PART II:  INTERPRETING THE REPORTS

   Introduction ....................................................    1
   The Solar Terrestrial Forecast and Review .......................    2
   Summary of Solar Terrestrial Activity ...........................    2
   Short Term Solar Terrestrial Forecast ...........................    5
   Solar Region Summary ............................................    6
   Geomagnetic Activity Summary ....................................    8
   10-Day Geomagnetic Activity Forecast ............................    9
   Graphical Analysis of Solar Activity ............................   10
   20-Day Solar Activity Forecast ..................................   10
   HF Radio Signal Propagation Predictions .........................   11
   VHF Propagation Prediction Charts ...............................   14
   Auroral Activity Predictions ....................................   15
   Monthly Solar Terrestrial Review ................................   16
   Geomagnetic Storm Alert .........................................   16
   Concluding Remarks ..............................................   17


Comments and/or questions regarding this document are welcomed and may be
directed to "[e-mail]".

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

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

End of SPACE Digest V12 #681
*******************