From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Ulysses Update - 11/02/92
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.3-4   
Keywords:  Ulysses, JPL, ESA
Reply-To: baalke@kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Sat, 7 Nov 1992 02:39:45 GMT

Forwarded from Peter Beech, Ulysses Mission Operations Manager

SUBJECT:  ULYSSES MISSION OPERATIONS REPORT No. 115

PERIOD:   27th October to 2nd November 1992

1.   MISSION OPERATIONS

     Experiment reconfigurations have been carried out as
     required.

     On 2nd November a KEP (Energetic Particles instrument)
     EPAC in-flight calibration was carried out.

     Routine Earth pointing manoeuvres were performed on 30th
     October and 2nd November.

     On 2nd November the STO (Radio and Plasma Waves instrument)
     daily command sequences were delayed due to commanding problems
     at Goldstone.  The sequences were transmitted later from Canberra.

     An average of 96.3 % data recovery was achieved during the
     reporting period.

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

     1024 bps 41.94 %
      512 bps 54.06 %

     A reduction in the number of ranging passes continued during
     the reporting period in order to improve the poor signal to
     noise ratio encountered at the present large spacecraft-
     Earth distances.

2.   SPACECRAFT STATUS

     POWER

     Nominal.
     Estimated S/C power consumption 258 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, with at least one 70m station pass per week to
     support ranging.

     Received downlink level -144 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 -126 dBm.

     DATA HANDLING

     The anomaly on CTU2 reported in previous Operations Reports
     is still under investigation.  However, some conclusions
     have now been reached which point to an electrical
     connection between two adjacent data lines as a result of
     component failure.  The operational impact of this anomaly
     is being studied by both the Spacecraft Control Team and the
     instrument teams in the event that this CTU would have to be
     configured for operational use.

     THERMAL

     Nominal.

3.   FLIGHT DYNAMICS

     Solar Aspect   The angle increased from 8.12 on
     Angle (deg.)   27th October to 8.83 on 2nd November.

     Sun-Probe-Earth  The angle increased from 7.97 on
     Angle (deg.)     27th October to 8.62 on 2nd November.

     Spin Rate               4.981 rpm.

4.   ORBITAL DATA

     Data taken at 13:00 PDT on 2nd November.
     Distance from Earth                857,316,852 km.
     Velocity relative to the Earth         128,217 km/hr.
     Velocity relative to the Sun            32,260 km/hr.
     Ecliptic latitude                         12.3 deg/south

5.   PLANNED OPERATIONS

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

     On 4th November a HED (Magnetic Field instrument) calibration
     will be carried out.

     Earth pointing manoeuvres will be performed on 6th and
     10th November.

     Periods of 2048 bps at low antenna elevations will be
     avoided to improve the signal to noise ratio in the coming
     months.  This will slightly reduce the percentage of 1024
     bps real-time data received.  During this period, 70m passes
     will also be scheduled to perform ranging at large
     spacecraft-Earth distances while maintaining the desired bit
     rates.

6.   GROUND SEGMENT

     The ground segment performed nominally during the reporting
     period except for the commanding problems described above.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     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. 
|_____|/  |_|/       |_____|/                     | 

Newsgroups: sci.space.news