Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_0/V13_065.TXT

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Subject: SPACE Digest V13 #065

SPACE Digest                                      Volume 13 : Issue 65

Today's Topics:
               Update on CRRES releases
           Re: space news from Dec 17 AW&ST
              Magellan Update - 01/17/91
             Galileo Update #2 - 01/17/91

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
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Date:    Wed, 16 Jan 1991 23:25:14 CST
From: [e-mail] (Pat Reiff [phone]-2650)
Subject: Update on CRRES releases
X-Vmsmail-To: SMTP%"[e-mail]"

In response to queries on the net, here's the results from the last
successful CRRES release (and the time of the next window, at 11:05 CST
on 1/17).  Following the first message, will be a repeat of the science
objectives and a complete list of the release windows.  Note that many
of the windows remaining on the list will not be used because of the
success of the releases so far.  I'll try to find out the subset which
is really remaining and post it.  Does anyone have a copy of MACSAT to
get altitudes and azimuths from satellite elements?  If so, I can post
the elements as well......Pat

CRRES BOMBS THE PLASMAPAUSE!!!!!

The G-4 release was performed January 16, 1991 at 06:25:00. The
location of the release was right on the plasmapause boundary, as
determined by simultaneous measurements with the Iowa plasma wave
instrument. Howard Singer reported an initial compression of 10 gammas,
followed by a diamagnetic reduction from an ambient value of 250 gammas
down to 110 gammas. This reduction lasted for about 40 seconds.

The CRRES on-board photometer saw the sun glint from the canister and in
comparison with the particle data, the direction of the canister
relative to the spacecraft was determined to be perpendicular to the
magnetic field direction.

The optical data were all excellent. Optical data was recorded at White
Sands, Los Alamos, Millstone Hill, Long Key, St. Croix, Arecibo, Cerro
Tololo, and El Leoncito. The northern and southern tips of the
field-aligned ion streak were tracked for 45 minutes following the
release.

The next opportunity will be a high altitude lithium release on January
18 with windows beginning at 0500 UTC.


David L. Reasoner

January 16, 1991

CRRES JANUARY HI-ALT RELEASE CAMPAIGN

The CRRES Program is on schedule for a series of high-altitude chemical
releases in January, 1991. The scientific objectives of these releases may
be grossly characterised as 1. Formation of Diamagnetic Cavities; 2.
Cold-Plasma Seeding experiments to induce artificial precipitation; 3.
Magnetospheric Injection and Ion Tracing; and 4. Plasmoid Formation. The
releases will be observed with an extensive network of ground and aircraft
sites. Ground sites will be located at Los Alamos, White Sands, Millstone
Hill (radar and optical), Rosemary Hill, FL; and Long Key, FL in the
United States. Carribean sites are St. Croix, USVI; Arecibo, P.R.; and
Bonaire, Netherlands Antilles. South American sites will be located at
Recife, Brazil; El Leoncito, Argentina; Cerro Tololo, Chile; and Baltra
Island, Galapagos Islands, Ecuador. Three research aircraft carrying
optical instruments will be used. Two USAF KC-135s will operate from K.I.
Sawyer AFB near Marquette, Michigan and will fly tracks in Canada to look
for artificially-induced precipitation. The Argentine/CNIE B-707 will
operate from Recife, Brazil and will view the releases directly, tracing
the ion motions.

We expect considerable public interest as the releases will be very
visible. The lithium releases will, 30 seconds following ignition, be 0.5
degree is visual diameter with an intensity at 6708 Angstroms of 1
megaRayleigh, i.e. a large and as bright as the full moon (Rev 6-12). We
think someone might notice.

A "Hot-Line" information number has been established at 205-544-5356. The
latest release information will be available in the form of a recorded
message.

Attached is a table of the release windows and types.



    CRRES RELEASE WINDOWS FOR JANUARY, 1991
    REVISED 01/05/91  BASED ON ORBIT PREDICTS EPOCH 01/04/91

    ALL POSSIBLE WINDOWS ARE SHOWN. TOTAL RELEASES = 7.
    3 SMALL BARIUM, 1 LARGE BARIUM, 3 LITHIUM.

    EACH WINDOW IS EITHER A SINGLE POINT IN TIME (SINGLE LINE)
    OR A SPAN (PAIRED LINES).

    FOR EACH WINDOW THE SATELLITE POSITIONS AT THE OPENING AND CLOSING
    ARE LISTED.

    ALL LATITUDES NORTH U.O.S.  ALL LONGITUDES ARE WEST

    RELEASE TYPES: 1 = SMALL BARIUM 1.5 KG, 2 = LARGE BARIUM 10.8 KG,
                   3 = LITHIUM .74 KG

    ALL TIMES ARE UTC (A.K.A. GREENWICH MEAN TIME). PST = UTC-8,
    MST=UTC-7, CST=UTC-6, EST=UTC-5.

    DATE     TIME    LAT.   LONG.    ALT.    REL. TYPE     SUCCESS NOTES
                                     (KM)

    JAN 11   0143     18.1      58.5    14899   1  POSTPONED

    JAN 13   0218     16.8     103.5     6149   1  SUCCESSFUL! G-2 (Sm Barium)
    JAN 13   0258     18.0      78.1    15000  (Not done because prior was done)

    JAN 13   0649      8.7      85.0    33559  2,3  Done at 0705 (below)
    JAN 13   0844      3.2      96.2    28677

    JAN 13   0705      8.0      86.7    33410  ###  SUCCESSFUL! G-7 (Lg Li)

    JAN 15   0332     17.0     123.6     6091   1   not done
    JAN 15   0412     17.9      97.9    14992

    JAN 15   0537     14.2      91.9    26972   1   not done

    JAN 15   0710     10.4      99.1    32879   #####  not done

    JAN 15   0806      8.1     105.1    33547   2,3  *  not done
    JAN 15   0958      2.7     116.0    28687

    JAN 16   0348      7.8      41.0    33547   2,3  *    G-4 successful @
    JAN 16   0539      2.5      51.8    28740           0625 UT

    JAN 18   0028     17.3      78.7     6137   1    won't be done
    JAN 18   0228     13.9      47.3    26511

    JAN 18   0503      7.4      61.0    33565   2,3  *  NEXT CANDIDATES
    JAN 18   0654      2.0      71.8    28680


    DATE     TIME     LAT.     LONG.    ALTITUDE  REL. TYPE
                               (WEST)   (KM)

    JAN 20   0142     17.4      98.7     6127   1
    JAN 20   0221     17.6      73.5    14828

    JAN 20   0345     13.4      67.4    26788   1

    JAN 20   0454     10.4      72.1    31897   2,3  *
    JAN 20   0807      1.5      91.6    28724

    JAN 20   0850      1.2 S    94.0    24538   1

    JAN 22   0459     13.1      87.1    26790   1

    JAN 22   0608      9.9      91.9    31905   2,3  *
    JAN 22   0922      1.0     111.4    28699

    JAN 23   0552      2.5 S    47.9    23740   1

    JAN 24   0915      7.1     117.1    33462   2,3  *
    JAN 24   1034      0.5     131.1    28748

    JAN 25   0813     10.6 S    61.2    12757   1
    JAN 25   0843     16.6 S    38.9    5799

    * NOTES (APPLIES TO G5, G6, G7, G10 WINDOWS):

    1. WINDOWS ON 1/13, 1/15, 1/16, AND 1/18 OPENED AT 1 H 25 M AFTER
       END OF ECLIPSE AND CLOSED WHEN GEOCENTRIC ALT. < 5.5 Re.

    2. WINDOW ON 1/20 OPENED BY ALT > 6 Re AND CLOSED BY ALT < 5.5 Re.

    3. WINDOWS ON 1/22 AND 1/24 OPENED BY MOONSET AT CHURCHILL AND
       CLOSED BY ALT < 5.5 Re.

    4. ##### DENOTES PRIME G-7 (TYPE 3) RELEASE POINT.


    ***********************************************
    * RELEASE INFORMATION HOT LINE   205-544-5356 *
    ***********************************************
------
From the First Space Science Department in the World:
                                                    :      _^ ^_    ____
     Patricia H. Reiff                              :     / O O \   |GO \
     Department of Space Physics and Astronomy      :     \  V  /   |OWLS\
     Rice University, Houston, TX 77251-1892        :    / ""R"" \__/
     internet:  [e-mail]  (128.42.10.3)    \ ""U"" /
     SPAN:      RICE::REIFF                         :    _/|\ /|\_
     GTEtelemail:  [preiff/kosmos] tm44/usa         :

"Why does man want to go to the Moon? ...  Why does Rice play Texas?"
   ....JFK, Rice Stadium, 1962

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

Date: 17 Jan 91 16:32:38 GMT
From: julius.cs.uiuc.edu!wuarchive!rex!rouge![e-mail]  (Fraering Philip)
Subject: Re: space news from Dec 17 AW&ST

Comment regarding Broadcast CD-quality sound:

With all of the bilge being broadcast over the airwaves today, what
would be the point? After all, if people listened to more classical
or jazz or maybe new-age music, I could see the point. But, quite
simply, _Poison_ and _Nelson_ will still sound just as bad no matter
how good the dynamic response is.

;-) ;-) ;-) ;-) ;-)

Phil
[e-mail]

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

Date: 17 Jan 91 19:26:04 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan Update - 01/17/91


                         MAGELLAN STATUS REPORT
                           January 17, 1991

     The Magellan spacecraft and its radar system continue to perform
nominally after 803 mapping orbits.  During the seven STARCALS (star
calibrations) of the past 24 hours, one was unsuccessful due to rejects of
both stars, two were partially successful with one star reject, and the
remaining four were successful.  One of the "successful" attitude updates
accepted a false star interrupt, resulting in an incorrect attitude update of
0.09 degree.  The subsequent STARCAL was successful, correcting the error.
The High Gain Antenna offpoint of less than 0.09 for one orbit is within
mission specs.  An increase in star reference rejects has been expected as the
mission geometry changes.

     In response to the attitude reference alarms mentioned yesterday,
spacecraft controllers decided to raise the sun loss fault protection limit
from 11 to 30 minutes.  The fault protection keeps track of the amount of time
the sensors detect a "miscompare" or abnormal measurement in "time counts" of
0.53 seconds.  If the cumulative time counts reached the limit, the spacecraft
would put itself into a safing mode.  Although the counts remained far below
the limit, controllers felt it was prudent to set the higher time limit.
Again, this is believed to be a sun geometry problem which occurs periodically
when one sun sensor picks up the Venus albedo, while the other views only the
Sun.

     The weekly mapping command sequence, M1019, and its associated parameter
files will be sent to the spacecraft tomorrow.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 17 Jan 91 23:37:20 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Galileo Update #2 - 01/17/91


                           GALILEO STATUS REPORT
                             January 17, 1991

     As of noon (PST) Thursday, January 17, 1991, the Galileo spacecraft is
19,464,250 miles from the Earth and traveling at a heliocentric speed of
83,560 miles per hour; distance to the Sun is 84,388,010 miles (0.90 AU).
Round trip light time is 3 minutes, 26 seconds.

     A command was successfully sent on January 14 to reset the Command Loss
Timer to 240 hours, the planned value for this mission phase.

     Cruise Science Memory Readouts (MROs) were successfully completed on
January 14 for the EUV (Extreme Ultraviolet Spectrometer), DDS (Dust Detector)
and MAG (Magnetometer) science instruments.

     A SITURN to lead the sun was successfully performed on January 14.  The
turn, about 4.8 degrees, resulted in the spacecraft leading the sun by about
2.5 degrees.  Spacecraft performance during the activity was normal with no
anomalies/incidents observed.

     A series of Delay Action Commands (DACs) were sent on January 11 to cycle
the PLS (Plasma) instrument's replacement and supplemental electrical heaters
off/on, respectively.  This action was requested to better characterize the
thermal behavior of the PLS.  It was observed during the Earth 1 flyby that
the PLS experienced temperatures somewhat higher than anticipated; at no time,
however, was the health and safety of the instrument at risk.  The PLS
replacement heater was powered off and its supplemental heater activated on
January 11 via DACs.  DACs to reverse the heater configuration will be executed
on January 18 after sufficient thermal data is collected.

     The CDS "B" (Commmand Data Subsystem) memory copy activity was
successfully performed on January 17.  This activity demonstrated the second
in-flight use of the CDS copy capability.  For this "B" copy activity the
memory contents of CDS "B" elements (HLM1B, LLM1B, LLM2B, BUM1B) was copied
from prime memory into the extended memory.  Spot-check memory readouts were
subsequently performed and indicated no parity errors or anomalies.  This
activity completes the total copy of the CDS prime memory into the extended
memory and consequently reduces the time to recover from a future possible
chip/location failure.  Later in January a more complete CDS memory readout
will be performed for both CDS "A" and "B" sides.

     Commands to reduce the downlink data rate from 1200 bps to 40 bps uncoded
data were executed from the stored sequence on January 14.  The data rate
reduction is necessary until early April 1991 to ensure acceptable data
quality.  The data rate change occurred, as planned, and data was successfully
processed by the Ground Data System (GDS) without anomaly or incident.

     The spacecraft reached perihelion at 0.9 AU on January 11; thermal
profiles were near expected levels and no anomalies/incidents were observed.
From this point on, the spacecraft will recede from the sun as it travels
toward an encounter with asteroid Gaspra (about 2.1 AU) in late October 1991
prior to its planned second Earth flyby in December 1992.

     Due to the lack of valid star sets and required attitude constraints
between January 16 and February 25, the spacecraft's operating mode was changed
from the dual-spin mode to the all-spin mode.  In the all-spin mode, the
spacecraft will be commanded via the stored sequence to perform sun
acquisitions about every two days to maintain the tight sun point attitude
constraint necessary for thermal safety.

     The spacecraft has operated previously in the all-spin mode for extended
time periods without anomaly or incident.  The first time was between launch
and the first dual-spin transition (about L + 15 days), and the other about 20
days in response to spacecraft safing execution in January 90.  In spacecraft
safing, unlike those commanded from sequence, sun acquisitions were performed
automatically every 12 hours from the sun point fault protection algorithm.

     The AC/DC bus imbalance measurements exhibited some activity.  The AC
measurement increased about 2 DN and now reads 46.6 volts. The DC bus
measurement increased about 4 DN and now reads 13.9 volts.  No significant
changes were observed in either measurements when going from dual-spin to
all-spin operation.  All other power-related measurements and spacecraft
telemetry are normal.

     The GDS test program for the German Space Operations Center (GSOC) Cruise
Science operations support in September has started.  GSOC internal testing
of their telemetry system has been in process since early January.  Command
System testing is scheduled to start next week.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

End of SPACE Digest V13 #065
*******************