No. 157 - Final preparations for hibernation
The reporting period was fully dedicated to spacecraft preparation activities in readiness for the deep-space hibernation phase; a final solar arrays performance test was conducted at a heliocentric distance of 4.4 AU. The spacecraft is now configured for the hibernation entry operations planned for the beginning of next reporting period; all commands required for hibernation entry have been loaded on board in a disabled state.
During the reporting period, mission operations were conducted using the ESA New Norcia (NNO) ground station and the DSS 43 (Canberra, 70 metres) NASA Deep Space Network (DSN) antenna.
Main activities during reporting period
|141||21-May-2011||NNO 2643||Solar arrays test at 4.4 AU|
|144||24-May-2011||NNO 2646||Solid-state mass memory configured to use only one memory module|
|150||30-May-2011||NNO 2652||Switch on of second inertial measurement package and switch Safe Mode to low power conditions|
|151||31-May-2011||NNO 2653||Final verification of hibernation heaters and power consumption|
|152||1-Jun-2011||DSS-43 2654||Low gain antenna telecommand test|
|NNO 2654||Low gain antenna telecommand test and uplink of hibernation entry telecommands|
At the end of the reporting period on 18 February, Rosetta was at 556 million kilometres from the Earth (3.71 AU); one-way signal travel time was 1855 seconds (30 minutes 55 seconds). The distance to Sun was 600.86 million kilometres (4.01 AU).
|ALICE||The instrument is currently OFF.|
|CONSERT||The instrument is currently OFF.|
|COSIMA||The instrument is currently OFF.|
|GIADA||The instrument is currently OFF.|
|MIDAS||The instrument is currently OFF.|
|MIRO||The instrument is currently OFF.|
|OSIRIS||The instrument is currently OFF.|
|ROSINA||The instrument is currently OFF.|
|RPC||The instrument is currently OFF.|
|RSI||The USO is OFF since 12 May 2011 (DoY 132/2011).|
|VIRTIS||The instrument is currently OFF.|
|Lander (Philae)||The instrument is currently OFF.|
|SREM||The instrument is OFF with standard settings since 31 May 2011 (DoY 151/2011).|
The spacecraft is now fully configured for the final operations of the hibernation entry phase. The hibernation entry window opens now and extends till the end of July; four slots have been allocated for the entry operations (8 and 22 June, 6 and 20 July) and everything is ready for the first one. Remaining activities will be performed as part of the entry operations. All time-tagged commands are on board in a disabled status; few manual activities remain to be done before the spin-up manoeuvre. Following successful spin-up and hibernation entry, ground stations will still look for a possible signal from the spacecraft for a week, in case multiple failures occurred at the time of hibernation entry. In the event that no signal is received during this period, the spacecraft will be declared to be in hibernation mode.
Summary of upcoming events:
- 06 June 2011: Wake-up time programmed on-board
- 07 June 2011: Configuration of spin-up parameters and final go/no-go
- 08 June 2011: Spin-up and Hibernation entry (1st slot in the available window)
- 14 June 2011: End of nominal passive monitoring phase (in case of successful hibernation entry)
- 20 January 2014, 10:00 UTC: Wake-up and warm-up phase
- 20 January 2014, 17:00 UTC: Expected downlink signal from the spacecraft