From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Ulysses Update - 08/24/92
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: Fri, 28 Aug 1992 00:44:21 GMT

Forwarded from Peter Beech, Ulysses Mission Operations Manager

SUBJECT:  ULYSSES MISSION OPERATIONS REPORT No. 105

PERIOD: 18th to 24th August 1992

1.   MISSION OPERATIONS

     Experiment  reconfigurations  have  been  carried  out  as
     required.

     BAM-I (Solar Wind Plasma) counter overflows were observed
     during the  reporting period.  The cause is under investigation
     by the instrument team.

     Routine Earth pointing manoeuvres were performed on 19th and
     23rd August.

     An  average of 97.2 % data recovery was achieved during  the
     reporting period.

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

     1024 bps 44.6 %
      512 bps 52.6 %

     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 260 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 -148 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 -128 dBm.

     DATA HANDLING

     The  anomaly on CTU2 reported in previous Operations Reports
     is still under investigation.

     THERMAL

     Nominal.

3.   FLIGHT DYNAMICS

     Solar Aspect   The angle decreased from 2.67 on
     Angle (deg.)   18th August to 1.92 on 24th August.

     Sun-Probe-Earth  The angle decreased from 2.66 on
     Angle (deg.)     18th August to 1.97 on 24th August.

     Spin Rate               4.982 rpm.

4.   ORBITAL DATA

     Data taken at 13:00 PDT on 24th August.
     Distance from Earth                938,429,907 km.
     Velocity relative to the Earth          113,963 km/hr.
     Velocity relative to the Sun              30,911 km/hr.
     Ecliptic latitude                          8.8 deg/south

5.   PLANNED OPERATIONS

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

     Earth pointing manoeuvres will be performed on 26th and
     29th August.

     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 with the exception of a 56 minute data loss caused by
     an oil leak in the antenna gearbox at DSS-61 (Madrid 34
     meter antenna) on 20th August.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | baalke@kelvin.jpl.nasa.gov
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Optimists live longer
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | than pessimists.
|_____|/  |_|/       |_____|/                     | 

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