[meteorite-list] Rosetta Update - March 15, 2004

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:50 2004
Message-ID: <200403160122.RAA28264_at_zagami.jpl.nasa.gov>


Initial Commissioning Activities
European Space Agency
March 15, 2004


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
           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.
Received on Mon 15 Mar 2004 08:22:16 PM PST

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