No. 127 - Preparations for the Deep Space Hibernation Mode test
Safe mode recovery
The safe mode occurred on 1 January in the middle of a week between two ground communication passes. On 4 January the spacecraft was monitored again and then fully recovered over the next 3 passes.
DSHM test preparations
The DSHM test will take place between 20 and 27 January 2010, in the next reporting period. During the deep space hibernation mode the spacecraft will be spin-stabilized. The full set of commands required to perform the spacecraft spin-up and DSHM entry are loaded on-board. Rosetta is now configured for the DSHM test and only few real-time activities are planned for the next days to complete the preparations. For a summary of the planned activities during the DSHM test, see below.
LGA telecommand link test
On 11 January a test was successfully completed to characterize the telecommand link performance on the low-gain antenna (LGA). The test was performed both on the ESA New Norcia (NNO) ground station and the NASA DSN ground station Goldstone (DSS-14).
During the reporting period, mission operations have been conducted with support of the ESA New Norcia ground station.
| DOY | Date | Pass | Main Activity |
| 362 | 28/12/09 | NNO 2133 |
Monitoring pass |
| 004 | 04/01/10 | NNO 2140 |
Safe mode recovery |
| 005 | 05/01/10 |
NNO 2141 |
Safe mode recovery |
| 007 | 07/01/10 |
NNO 2143 |
Safe mode recovery |
| 008 | 08/01/10 |
NNO 2144 |
Monitoring pass |
| 009 | 09/01/10 |
NNO 2145 |
Monitoring pass |
| 011 | 11/01/10 | DSS-14 2147 NNO 2147 |
LGA telecommand link test |
| 013 | 13/01/10 | NNO 2149 |
Monitoring pass |
| 015 | 15/01/10 |
NNO 2151 |
Monitoring pass |
At the end of the reporting period (DoY 015) Rosetta was at 45.24 million km from Earth (0.3 AU) and the one-way signal travel time was 151 seconds. The distance to the Sun was 183.33 million km (1.22 AU).
DSHM test - planned activities
The test of the spacecraft's deep space hibernation mode will take place between DoY 020 and DoY 027. After a go/no-go decision early in the afternoon on DoY 020 the spacecraft will be spun-up several hours later; during the hibernation mode Rosetta will be spin-stabilized as opposed to maintaining a 3-axes stabilized attitude.
When the final checks after the spin-up are completed by the mission control team at ESOC, the entry in hibernation will be authorised, nominally in the morning of DoY 021. The spacecraft will then enter the deep space hibernation mode and switch OFF the subsystems for attitude and orbit control (AOCS) and for telemetry, tracking & commanding (TTC).
During the DSHM test the spacecraft transmitter will be switched ON for monitoring purposes. The spacecraft will remain in DSHM configuration for a whole week and will be monitored daily for about 8 hours.
Early in the morning on DoY 027 the spacecraft will autonomously trigger its exit from hibernation by starting the STR warm-up phase lasting 6 hours. At the end of this phase the spacecraft will perform a transition to safe mode. Next it will spin-down, re-establish a 3-axes stabilised attitude, and finally re-establish the telemetry and telecommand link with the ground station.
At this stage the mission operations team will resume control over the spacecraft and start the lengthy recovery process.
Timeline of events:
| DOY | Date | Activity |
| 015 | Fri 15/01/10 | Spacecraft monitoring; Uplink of final commands |
| 018 | Mon 18/01/10 | Spacecraft monitoring |
| 019 | Tue 19/01/10 | Spacecraft monitoring |
| 020 | Wed 20/01/10 | Spin-up; DSHM entry |
| 021 | Thu 21/01/10 | DSHM |
| 022 | Fri 22/01/10 | DSHM |
| 023 | Sat 23/01/10 | DSHM |
| 024 | Sun 24/01/10 | DSHM |
| 025 | Mon 25/01/10 | DSHM |
| 026 | Tue 26/01/10 | DSHM |
| 027 | Wed 27/01/10 | DSHM exit; Transition to Safe Mode; Spin-down; Spacecraft recovery |
| 028 | Thu 28/01/10 | Spacecraft recovery |
| 029 | Fri 29/01/10 | Spacecraft recovery |
| 032 | Mon 01/02/10 | Spacecraft monitoring |
Spacecraft
Payload
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 instrument is muted. It was switched OFF by the safe mode on DoY 001 and switched ON again as part of the recovery actions on DoY 005.
The instrument will stay ON during the DSHM test (DoY 020 through 027). After this test the RSI will be switched OFF by the spacecraft's transition to safe mode. As part of the recovery actions following the DSHM test the RSI will then again be switched ON.
VIRTIS
The instrument is currently OFF.
LANDER Philae
The instrument is currently OFF.
SREM
The instrument is currently OFF following the safe mode on DoY 001. In view of the upcoming DSHM test it was decided to leave the instrument OFF till after this test.
Future Milestones
A test of the deep space hibernation mode (DSHM) will take place between 20 and 27 January.
Following the DSHM test, at the end of the spacecraft recovery and reconfiguration activities, an attempt to re-lubricate reaction wheel B will be conducted.
The following weeks will be dedicated to payload check-out 12 (PC12) advanced activities.
Rosetta is cruising towards asteroid Lutetia. The encounter with the asteroid will take place in July 2010.
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Legal disclaimer
This report is based on the ESOC mission operations report, WOR #127. Please see the copyright section of the legal disclaimer (bottom of this page) for terms of use.