No. 148 - Pre-hibernation payload checkout
The behaviour of reaction wheel C has greatly improved after the second relubrication exercise and its performance is now considered to be very close to nominal.
During the reporting period, mission operations were conducted using the ESA New Norcia (NNO) ground station and the DSS-14 (Goldstone, 70 metres), DSS-15 (Goldstone, 34 metres), DSS-26 (Goldstone, 34 metres) and DSS-54 (Madrid, 34 metres) NASA Deep Space Network (DSN) antennas.
|Main activities during reporting period|
|333||29-Nov-2010||NNO 2470||RPC Ion and Electron Sensor (IES) EEPROM Refresh|
|335||1-Dec-2010||NNO 2472||PC13 - Lander|
|336||2-Dec-2010||NNO 2473||PC13 - Lander|
|337||3-Dec-2010||NNO 2474||PC13 - Lander|
|PC13 - Lander & ROSINA|
|342||8-Dec-2010||NNO 2479||PC13 - Lander & ROSINA|
|343||9-Dec-2010||DSS-15 2480||PC13 - ROSINA|
|348||14-Dec-2010||NNO 2485||PC13 RSI|
At the end of the reporting period on 17 December, Rosetta was at 649 million km from Earth (4.33 AU); the one-way signal travel time was 36 min 05 sec (2165 sec). The spacecraft's distance from the Sun was 555 million km (3.71 AU).
|ALICE||The instrument is currently OFF. PC13 activities have been conducted without problems.|
|CONSERT||The instrument is currently OFF. PC13 activities have been conducted without problems.|
|COSIMA||The instrument is currently OFF. PC13 activities have been conducted without problems.|
|GIADA||The instrument is currently OFF. PC13 activities have been conducted without problems.|
|MIDAS||The instrument is currently OFF. PC13 activities have been conducted without problems.|
|MIRO||The instrument is currently OFF. PC13 activities have been conducted without problems.|
|OSIRIS||The instrument is currently OFF.|
|ROSINA||The instrument is currently OFF. The instrument software was updated on both the nominal and redundant sides; on 9 December (DoY 343), the instrument was activated to calibrate the spacecraft background environment in the same attitude as during the Lutetia fly-by.|
|RPC||The instrument is currently OFF. The Ion and Electron Sensor (IES) EEPROM software was fully refreshed and PC13 activities successfully completed. A small number of error events were recorded during the activities; however none of them are expected to affect operations.|
|RSI||The USO is ON/muted since 3 February 2010 (DoY 032/2010). On 14 December (DoY 348) the standard checkout was conducted. During the test, the transponder showed narrow band lock on the uplink at the switchover times from the temperature-controlled crystal oscillator to the ultra-stable oscillator and vice versa. This unexpected behaviour will be analysed.|
|VIRTIS||The instrument is currently OFF. PC13 activities have been conducted without problems.|
|Lander (Philae)||The instrument is currently OFF. PC13 activities, that included the uplink of a complete new software version on the CDMS, have been conducted according to plan. The few problems recorded during the test were promptly recovered and the instrument was declared ready for the hibernation phase.|
|SREM||The instrument is ON with standard settings since 3 February 2010 (DoY 032/2010).|
Future milestonesThe spacecraft is now fully configured for the execution of the first rendezvous manoeuvre that is planned for the second half of January 2011, with the first burn leg on 17 January. Due to its magnitude, this manoeuvre has been split into five nominal burns plus an optional extra one in the event that a final correction is needed. The detailed plan for the burns is given in the table below.
|First Rendezvous Manoeuvre Burn Details|