From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Ulysses Update - 10/12/92
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: Thu, 15 Oct 1992 02:48:16 GMT

Fowarded from Peter Beech, Ulysses Mission Operations Manager

SUBJECT:  ULYSSES MISSION OPERATIONS REPORT No. 112

PERIOD:   6th October to 12th October 1992

     On 6th October Ulysses achieved two years in orbit.

     Experiment  reconfigurations have been carried  out  as
     required.

     On 6th October a KEP GAS (Interstellar Neutral Gas)
     instrument health check was carried out.

     On 7th October a HED (Magnetic Field) instrument
     calibration was carried out.

     Routine Earth pointing manoeuvres were performed on 7th
     and 10th October.

     An  average  of 98 % data recovery was achieved  during
     the reporting period.

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

     1024 bps 46.76 %
      512 bps 50.97 %

     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 259 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 -145 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 -124 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 5.34 on
     Angle (deg.)   6th October to 6.21 on 12th October.

     Sun-Probe-Earth  The angle increased from 5.33 on
     Angle (deg.)     6th October to 6.12 on 12th October.

     Spin Rate               4.981 rpm.

4.   ORBITAL DATA

     Data taken at 13:00 PDT on 12th October.
     Distance from Earth                898,526,915 km.
     Velocity relative to the Earth         124,757 km/hr.
     Velocity relative to the Sun            31,910 km/hr.
     Ecliptic     latitude                              11.2
     deg/south

5.   PLANNED OPERATIONS

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

     On  18th  October a HUS (Solar X-Rays) instrument end-to-end
     Datation  test  will take place at Goldstone.

     On  19th  October a KEP in-flight calibration  will  be
     carried out.

     On 21st October a HED calibration will be carried out.

     Earth  pointing manoeuvres will be performed  on  13th,
     17th and 20th October.

     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.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | baalke@kelvin.jpl.nasa.gov
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Einstein's brain is stored
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | in a mason jar in a lab
|_____|/  |_|/       |_____|/                     | in Wichita, Kansas.