U2/PB/JS/1                 06/12/95

          Ulysses Mission Operations Manager

          Distribution






ULYSSES MISSION OPERATIONS REPORT No.  275


PERIOD:    28th November to 4th December 1995


1.   MISSION OPERATIONS

Experiment reconfigurations have been carried out as required.

KEP GAS configurations continued throughout the reporting period.

On 28th November a successful downlink test was conducted with the new DSS24 site at Goldstone.

On 29th November a HED calibration was carried out.

On 30th November a successful uplink test was conducted with the DSS24 site at Goldstone.

On 2nd and 3rd December special operational techniques involving both tape recorders in tandem and then playing them back at 8Kbps were employed to avoid any loss of data as a result of the special DSN support requirements put in place for the SOHO launch.

On 4th December a KEP in flight calibration was carried out.

Open loop slew Earth pointing manoeuvres were performed on 28th November and 2nd December.

An average of 97.9 % data recovery was achieved during the reporting period.

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

1024 bps:		36.9%

512 bps:		60.7 %



2.   SPACECRAFT STATUS

POWER

Nominal.

Estimated S/C power consumption 243 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.

Scheduled support is provided by the DSN complex at Goldstone with occasional support from Madrid.

Received downlink level -137 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 -121 dBm. (from 34 meter S-band).


DATA HANDLING

Nominal.  DSU2 in use.  Both recorders were used during the special operations on 2nd and 3rd December.


THERMAL

Nominal.



3.   FLIGHT DYNAMICS

Solar Aspect       The angle reduced from 19.98 on 28th November
Angle(deg.)        to 19.78 on 4th December.

Sun-Probe-Earth    The angle reduced from 19.93 on 28th November
Angle(deg.)        to 19.78 on 4th December.

Spin rate           4.954 rpm.



4.   ORBITAL DATA 

Data taken at 00:00:00 UTC on 4th December.

Distance from the Earth                    427,039,359 km.
Distance from the Sun                      430,548,510 km.
Velocity relative to the Earth                  45,828 km/hr.
Velocity relative to the Sun                    67,683 km/hr.
Ecliptic latitude                                 64.0 deg/north
Heliographic latitude                             57.6 deg/north



5.   PLANNED OPERATIONS

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

KEP GAS configurations will continue throughout the next reporting period.

On 5th December a SIM HET calibration and a HUS datation test will be carried out.

On 11th December a KEP in flight calibration will be carried out.

Open loop slew Earth pointing manoeuvres will be performed on 6th and 10th December.



6.   GROUND SEGMENT

The ground segment performed nominally during the reporting period.



Peter Beech



Ulysses Mission Operations Report
6/12/95
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