No. 3 - Initial Commissioning Activities
15 March 2004 16:26
In the reporting period the Rosetta control at ESOC has been moved to the Dedicated Control Room, ground coverage has been reduced to a single ground station (New Norcia, covering about 12 hours per day) and spacecraft and payload commissioning activities have begun.
All planned activities were successfully completed, including commissioning of the X-band equipment, activation of the fourth reaction wheel, calibration solar array flexible modes and sun sensor misalignment, testing of the Star Trackers in the nominal cruise attitude (+X sun pointing).
The first three instruments (Cosima, Consert and Osiris) were activated and their first slot of commissioning activities successfully completed. The first payload appendage (Consert antenna) was deployed.
The spacecraft is kept in the "tilted" attitude achieved during LEOP and slewed to +X sun pointing only when payload operations require it. This is to keep the High Gain Antenna mechanism cooler following the unexpected high temperature measured in LEOP. This new attitude has no immediate impact on operations, except that it imposes a higher than planned number of attitude slews and consequently of reaction wheels off-loading cycles.
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 072, 09:30) Rosetta was at 3.2 million km from the Earth. The return signal travel time was 21.6 seconds.