No. 4 - Spacecraft Commissioning Continues
24 March 2004 15:15
Report for week 12 to 19 March
Since the last status report there have been two major areas of commissioning activity: for the first five days the focus was on the lander; followed later by the various plasma detection packages on the orbiter.
The Lander activities were all performed successfully and completed well within the scheduled time. This enabled the early execution of a number of activities initially planned for a later slot. Only one activity, the Lander MSS check, was postponed to allow re-definition of the procedure in view of the fact that the launch locks were released earlier than planned (on mission day 1).
In the last two days the Rosetta Plasma Consortium (RPC) commissioning activities started. The first day saw the successful activation and check out of all RPC instruments using the main power supply and data processing unit. During a repeat test using the redundant chain a sudden interruption in telemetry and drop in current consumption was detected. Investigations suggest a failure in the redundant power supply.
On the last day of the reporting period the spacecraft booms carrying the RPC MIP (Mutual Impedance Probe) and LAP (Langmuir Probe) instruments were successfully deployed using the primary systems. The instruments were active during the deployment and confirmed the successful operation via readings in their science telemetry. In order for further analysis to take place on the failure in the redundant power supply all remaining RPC activities have been postponed to a later date.
The table below shows a chronology of the main activities in the reporting period:
At the end of the last New Norcia pass in the reporting period (DOY 079, 09:00) Rosetta was at 5.5 million km from the Earth. The return signal travel time was 36.8 seconds.
Payload commissioning will continue throughout March, April and May. During the coming week commissioning will commence on ROSINA, ALICE and VIRTIS.