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No. 127 - Preparations for the Deep Space Hibernation Mode test

No. 127 - Preparations for the Deep Space Hibernation Mode test

Report for Period 26 December 2009 to 15 January 2010The reporting period covers three weeks of operations for the Rosetta spacecraft. Early in the reporting period on DoY 001 the spacecraft experienced a safe mode. This was triggered by a problem on one of the subsystems' Remote Terminal Units (RTUs). The spacecraft was fully recovered and the cause proved to be not permanent.During the last week of the reporting period final preparations for the forthcoming test of the deep space hibernation mode (DSHM) were conducted. This test will validate the operating mode that the spacecraft will use for a period of about 2.5 years, from June 2011 till January 2014, during its passive cruise to comet 67P/Churyumov-Gerasimenko.

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
Monitoring pass

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.

Last Update: 1 September 2019
11-Jul-2020 04:47 UT

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