From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Ulysses Update - 01/04/93
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41    
Keywords: Ulysses, JPL, ESA
Organization: Jet Propulsion Laboratory
Date: Mon, 11 Jan 1993 17:28:00 GMT

SUBJECT:  ULYSSES MISSION OPERATIONS REPORT No. 123

PERIOD:   29th December 1992 to 4th January 1993

1. MISSION OPERATIONS

     Experiment reconfigurations have been carried out as
     required.

     On 30th December a HED (Magnetic Field instrument)
     calibration took place.

     Routine Earth pointing manoeuvre were performed on 30th
     December and 3rd January.

     An average of 98.5 % data recovery was achieved during
     the reporting period.

     The percentage of data acquired as a function of bit rate
     is as follows:

     1024 bps 47.5 %
      512 bps 51.0 %


2.  SPACECRAFT STATUS

     POWER

     Nominal.
     Estimated S/C power consumption 257 watts.

     AOCS

     Nominal.

        TTC

     The spacecraft is currently configured with receiver 2 as
     the prime unit fed via the high gain antenna and with
     receiver 1 as backup fed through the low gain antenna
     (LGA-F). The downlink is provided through EPC2/TWTA2.


     The 34 meter ground stations are in use to support TTC
     operations.  Ranging from 34 meter ground stations is
     performed when the spacecraft is configured for bit
     rates of 1024 bps or less.  Ranging passes from 70 meter
     ground stations are also being taken periodically.

     Received downlink level -140 dBm.(34 meter) X-band.

     (Variations of up to 10 db. can be expected as a result
     of station antenna in use, local weather conditions, and
     spacecraft antenna off-pointing).

     Received uplink level -122 dBm.

        DATA HANDLING

     Nominal with the exception of the CTU#2 anomaly.

     THERMAL

     Nominal.


3.   FLIGHT DYNAMICS

     Solar Aspect   The angle reduced from 10.85 on
     Angle (deg.)   29th December to 10.44 on 4th January.

     Sun-Probe-Earth  The angle reduced from 10.81 on
     Angle (deg.)     29th December to 10.48 on 4th January.

     Spin Rate               4.980 rpm.


4.   ORBITAL DATA

     Data taken at 13:00 PDT on 4 January.
     Distance from Earth                691,402,951 km.
     Velocity relative to the Earth         127,174 km/hr.
     Velocity relative to the Sun            33,826 km/hr.
     Ecliptic latitude                         15.9 deg/south


5.   PLANNED OPERATIONS

     Routine data gathering operations will continue together
     with experiment reconfigurations as required.

     A SIM HET (Cosmic Ray instrument) calibration will be performed
     on 5th January and a LAN (Low Energy Charged Particles instrument)
     calibration performed on 8th January.

     Earth pointing manoeuvres will be performed on 7th and
     11th January.

     Periods of 2048 bps at low antenna elevations will
     continue to be avoided to improve the signal to noise
     ratio.  This will slightly reduce the percentage
     of 1024 bps real-time data received.


6.   GROUND SEGMENT

     The ground segment performed nominally during the
     reporting period with the except during the passes on
     1st January.

     A problem in the MCCC (Mission Control Computing Center)
     at JPL caused all data to be tagged with the year 1992 instead of
     1993.  The real-time SCMS was not able to file this data since the
     timekey was earlier than the first record in the history file.  The
     history files on the backup machine were cleared and this
     was used to file data while the problem was traced.
     Once the problem was fixed data were recalled into the
     real-time machine and properly filed in the history
     files.  No data were lost.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | baalke@kelvin.jpl.nasa.gov
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Choose a job you love, and
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/  |_|/       |_____|/                     | a day in your life. 

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