From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/06/92
News-Software: VAX/VMS VNEWS 1.3-4   
Keywords:  Galileo, JPL
Reply-To: baalke@kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Sat, 7 Nov 1992 08:19:12 GMT

Fowarded from Neal Ausman, Galileo Mission Director

                                    GALILEO
                        MISSION DIRECTOR STATUS REPORT
                                  POST-LAUNCH
                        October 30 - November 5, 1992

SPACECRAFT

1.  On October 31 and November 1, delta Differenced One-Way Range (DOR) passes
were performed over DSS-14/63 (Goldstone/Madrid) and DSS-14/43
(Goldstone/Canberra).  Initial results indicate three of the four delta DOR
passes were successfully performed.

2.  On November 2, a NO-OP command was sent to reset the command loss timer
to 264 hours, its planned value for this mission phase.

3.  On November 3, real-time commands were sent to change the downlink
telemetry rate from 1200 bps coded to 7.68 kbps coded.  This allowed the Heavy
Ion Counter (HIC) instrument to transmit Low Rate Science (LRS) data two days
earlier than planned in the background sequence, collecting data on recent
solar flare activity.

4.  On November 3, after the telemetry configuration to low rate science data
(7.68 kbps), visibility into the full engineering channels revealed that four
of the Ultraviolet Spectrometer (UVS) channels were not in their expected
state.  Preliminary analysis indicates that a bit flip in one memory location
apparently occurred between the first and second instrument memory readouts on
October 15, 1992.  The UVS team is still investigating the possible cause of
this anomaly.  The instrument health and safety are not threatened.

5.  On November 4, delta DOR passes were performed over DSS-14/63 and
DSS-14/43.  Initial results indicate the one of the two delta DOR passes were
successfully performed.

6.  On November 4, real-time commands were sent to verify the status of the
UVS microprocessor memory.  The memory readouts confirm that a bit flip is
still present in the same memory location.  Investigation into the cause of
the anomaly and actions to take are continuing.

7.  On November 5, real-time commands were sent to configure the System Fault
Protection (SFP) for the near Earth 2 operations.  Commanding was interrupted
for 1 hour 8 minutes due to a low power transmitter problem at DSS-63 (Madrid
70 meter antenna).  Commanding was then resumed and all command activities
completed.  Specifically, the Energetic Particle Detector (EPD) science
monitor was updated, thruster firing all clear response was enabled, and the
Plasma Wave (PWS) cold flag parameter was changed.

8.  The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 16DN to 17DN and now reads 17 DN (3.9 volts).
The DC measurement has changed significantly from 133 DN (15.6 volts) to
160 DN (18.9 volts) and now reads 137 DN (16.1 volts).  These measurement
variations are consistent with the model developed by the AC/DC special
anomaly team.

9.  The Spacecraft status as of November 5, 1992, is as follows:

       a)  System Power Margin -  82 watts
       b)  Spin Configuration - Dual-Spin
       c)  Spin Rate/Sensor - 3.15 rpm/Star Scanner
       d)  Spacecraft Attitude is approximately 7 degree
           off-sun (leading) and 8 degrees off-earth (lagging)
       e)  Downlink telemetry rate/antenna-7.68kbps (coded)/LGA-1
       f)  General Thermal Control - all temperatures within
           acceptable range
       g)  RPM Tank Pressures - all within acceptable range
       h)  Orbiter Science- UVS, 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 - 260 hours


GDS (Ground Data Systems):

1.  A Ground Data System Data Flow Test was conducted Tuesday, November 3
with the NIMS (Near Infrared Mapping Spectrometer) Processing Equipment (NPE)
following its relocation from 264-316 to 264-721.  The data flow test was
successful.  In addition, the 26 October Probe MRT (Mission Readiness Test)
post test analysis has been completed.  All test objective were met and the
test was considered successful.

2.  Since the start of 1200 bps telemetry operations last month, random
losses of data blocks have been noticed during Madrid passes.  The problem is
currently under investigation with resolution targeted by November 16th
before the start of the Probe Mission Sequence Test (MST) with the spacecraft
(November 20th).  Occurrences of the problem during the Madrid pass Thursday
were correlated with heavy communication loading including simultaneous passes
and VLBI (Very Long Baseline Interferometry) data replays.  The DSN (Deep
Space Network) is establishing procedures to monitor and minimize the
communication loads at Madrid during critical Earth 2 support.

TRAJECTORY

     As of noon Thursday, November 5, 1992, the Galileo Spacecraft trajectory
status was as follows:

	Distance from Earth         27,366,500 km (.18 AU)
	Distance from Sun           174,661,900 km (1.17 AU)
	Heliocentric Speed           111,600 km per hour
	Distance from Jupiter        944,473,000 km
	Round Trip Light Time        3 minutes, 0 seconds

SPECIAL TOPIC

1.  As of November 5, 1992, a total of 8636 real-time commands have been
transmitted to Galileo since Launch.  Of these, 3659  were initiated in the
sequence design process and 4977 initiated in the real-time command process.
In the past week, 52 real time commands were transmitted: 46 were initiated in
the sequence design process and 6 initiated in the real time command process.
In addition, 5911 mini-sequence commands have been transmitted since March
1991; 3753 were pre-planned and 2158 were not.  In the past week, no
mini-sequence commands were transmitted.  Major command activities this week
included commands to reset the command loss timer, switch to 7.68 coded
telemetry data, perform memory readouts of the UVS instrument, and update
system fault protection for near Earth 2 operations.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | baalke@kelvin.jpl.nasa.gov
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Give people a second 
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | chance, but not a third. 
|_____|/  |_|/       |_____|/                     | 

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