No. 32 - Final Week of 2nd Commissioning Phase
18 October 2004 14:25Report for week 8 to 15 October 2004
In this last week of the commissioning phase the spacecraft spent most of the time in contact with the ground, using DSN passes during the day and New Norcia during the night. This allowed an intense and ambitious operations plan to be executed. All planned payload commissioning activities were completed in the reporting period, including additional slots scheduled for COSIMA and RPC. The ROSINA final commissioning pass originally planned for 11 October has been cancelled due to on-going investigations on the instrument. Several commissioning and configuration activities were carried out on the spacecraft subsystems.
Concerning the payload, the last block of Lander commissioning activities was completed successfully at the beginning of the slot. Other successfully completed activities were:
RSI USO commissioning.
RPC LAP dance while outside coverage.
COSIMA emitters troubleshooting activities over DSN passes. Whilst Emitter C was successfully tested some open questions remain on the behaviour of Emitter A.
The second part of the Interference scenario, with most of the instruments again active in parallel, was successfully carried out. The timeline of activities was designed as a result of the experience and measurements made during the first interference scenario in September, to confirm or to refine the measurements.
On the subsystems side a patch to the DMS software was uplinked to apply a workaround to a problem discovered by ASTRIUM during ground testing with the handling of on-board events. The Star Tracker A was finally set to "dust" configuration and it is now identical to the setting of Star Tracker B. The final slot of TTC commissioning started on 14 October with the testing of both Medium Gain Antennas (X and S band).
The baseline attitude of the spacecraft was changed to +X Earth pointing (without bias) and will remain such until close to the Earth flyby. Before applying the new attitude a set of slews was carried out to calibrate the disturbance torques models for the next few months.
Full daily passes over the New Norcia station were taken throughout the week. In addition, four DSN passes of about 8 hours duration each were taken from the 12 - 15 October, to support additional CVP activities.
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 289) Rosetta was at 66.2 million km from the Earth. The one-way signal travel time was 3 minutes 40 seconds.