From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/03/92
Keywords: Galileo, JPL
Date: 4 Sep 92 07:40:50 GMT
Reply-To: baalke@kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
News-Software: VAX/VMS VNEWS 1.3-4

Forwarded from Neal Ausman, Galileo Mission Director

                                   GALILEO
                      MISSION DIRECTOR STATUS REPORT
                                POST-LAUNCH
                      August 28 - September 3, 1992

SPACECRAFT

1.  On August 31, a NO-OP command was sent to reset the command loss timer
to 264 hours, its planned value for this mission phase.

2.  On September 3, the Dual Drive Actuator (DDA) pulse mini-sequence No. 3
was uplinked to the spacecraft.  This mini-sequence covers spacecraft
activities from September 8 to September 11, 1992.  This mini-sequence
includes two 2-second DDA motor turn on pulses, one shortly after turning to
a 45-degree off-sun attitude and the other just before returning to a near
sun-pointed attitude. (See Special Topic No. 2.)

3.  On September 3, a routine sun vector update was performed.  This sun
vector is valid through October 5, 1992.

4.  The AC/DC bus imbalance measurements exhibited some change. The AC
measurement remained unchanged and reads 3.3 volts.  The DC measurement has
ranged from 120 DN (14.0 volts) to 132 DN (15.5 volts) and now reads 120 DN
(14.0 volts).  These measurement variations are consistent with the model
developed by the AC/DC special anomaly team.

5.  The Spacecraft status as of September 3, 1992, is as follows:

       a)  System Power Margin -  70 watts
       b)  Spin Configuration - Dual-Spin
       c)  Spin Rate/Sensor - 3.15 rpm/Star Scanner
       d)  Spacecraft Attitude is approximately 6 degrees
           off-sun (leading) and 27 degrees off-earth (lagging)
       e)  Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
       f)  General Thermal Control - all temperatures within
           acceptable range
       g)  RPM Tank Pressures - all within acceptable range
       h)  Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are
           powered on
       i)  Probe/RRH - powered off, temperatures within
           acceptable range
       j)  CMD Loss Timer Setting - 264 hours
           Time To Initiation - 256 hours


UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:

1.  The Dual Drive Actuator (DDA) pulse mini-sequence No. 3 memory load was
approved for transmission by the Project on September 2, 1992. (See Special
Topic No. 2.)

GDS (Ground Data Systems):

1.  The D1.0 deliveries will continue thru October 1992 and will provide
updates to uplink capabilities needed for Jupiter sequence planning and
developments activities as well as updates to downlink capabilities needed for
Earth 2 support.


TRAJECTORY

     As of noon Thursday, September 3, 1992, the Galileo Spacecraft trajectory
status was as follows:

	Distance from Earth         72,134,600 miles (.78 AU)
	Distance from Sun           145,608,000 miles (1.57 AU)
	Heliocentric Speed          53,600 miles per hour
	Distance from Jupiter       647,914,400 miles
	Round Trip Light Time       13 minutes, 2 seconds

SPECIAL TOPIC

1.  As of September 3, 1992, a total of 8113 real-time commands have been
transmitted to Galileo since Launch.  Of these, 3235  were pre-planned in the
sequence design and 4878 were not.  In the past week, 2 real time command
was transmitted and pre-planned in the sequence design.  In addition, 5677
mini-sequence commands have been transmitted since March 1991; 3519 were
pre-planned and 2158 were not. In the past week, 250 mini-sequence commands
were transmitted.  Major command activities this week included commands to
reset the command loss timer and to update the sun vector.

2.  The Dual Drive Actuator (DDA) pulse mini-sequence No. 3 covers spacecraft
activities from September 8 to 11, 1992.  The warming turn to a 45-degree
off-sun attitude along with the first DDA two second motor turn on pulse is
scheduled for September 8.  The spacecraft will remain at the warming attitude
for approximately 28 hours.  The second DDA two second motor turn on pulse is
scheduled just prior to turning back to approximately a 6 degree off-sun
attitude.  Sun gate data will be collected on September 10.  The star scanner
checkout along with the collection of wobble data is scheduled for
September 11.
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    /_ /|  /____/ \  /_ /|     Ron Baalke         | baalke@kelvin.jpl.nasa.gov
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
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