ESA Rosetta Status Report 15 Mar 2004

Summary

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:

Mission Day	Date	DOY	Main Activity
4	05/06.03.04	65/66	Reaction wheel friction test
5	06/07.03.04	66/67	X-band commissioning; Transponder ranging delay test
6	07/08.03.04	67/68	COSIMA commissioning
7	08/09.03.04	68/69	Star Trackers test in +X Sun pointing
8	09/10.03.04	69/70	Solar Array flexible modes; SAS misalignment calibration
9	10/11.03.04	70/71	CONSERT antenna deployment and commissioning
10	11/12.03.04	71/72	OSIRIS commissioning

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 retuen signal travel time was 21.6 seconds.