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No. 109 - Superior Conjunction Phase

No. 109 - Superior Conjunction Phase

Report for Period 6 December 2008 to 16 January 2009The reporting period covers six weeks of operations, during which Rosetta successfully passed the superior conjunction phase. The angular separation between the Earth and the Sun as seen from the spacecraft stayed below 3° (conjunction) between 17 December 2008 and 6 January 2009, with the minimum angular separation occurring on 27 December.

Spacecraft and ground segment performance during the reporting period have been nominal. Mission operations were conducted with the support of the ESA New Norcia (NNO) ground station. 

DOY Date Pass Main Activity
345 10/12/08 NNO 1749 Spacecraft configuration for conjunction phase
353 18/12/08 NNO 1757


357 22/12/08 NNO 1761


005 05/12/09 NNO 1775


012 12/01/09 NNO 1782

End of conjunction phase

At the end of the reporting period (DoY 016) Rosetta was at 479.74 million km from Earth (3.21 AU) and the one-way signal travel time was 1600 seconds. The distance to the Sun was 336.92 million km (2.25 AU). On 17 December 2008 Rosetta passed the aphelion of its current orbit around the Sun with a record distance of 338.63 million km (2.26 AU). On 25 December 2008 Rosetta was at the largest distance from the Earth reached so far: 485.12 million km (3.24 AU).


All instruments are now switched off except for the Standard Radiation Environment Monitor (SREM) that continues to run in the background.

The instrument is OFF.

The instrument is OFF.

The instrument is OFF.

The instrument is OFF.
On DoY 012 a new on-board control procedure (OBCP) was uplinked to handle emergency closure of the cover.

The instrument is OFF.

The instrument is OFF.

The instrument is OFF.

The instrument is OFF.

The instrument is OFF.

The instrument is muted.

The instrument is OFF.

The instrument is OFF.

Since DoY 339/2008 the accumulation settings are configured for conjunction mode.

Future Milestones

The spacecraft has gone through the conjunction phase and will now undergo a check-out phase which will include a passive payload check-out and spacecraft maintenance activities.

The active cruising phase will continue till March 2009 when Deep Space Manoeuvre 4 will be conducted in preparation of the third and last Earth swing-by planned for 13 November 2009. The manoeuvre will be followed by a short tracking campaign with the spacecraft being configured for a near-Sun hibernation phase to last till beginning of September 2009.

Legal disclaimer
This report is based on the ESOC mission operations report, WOR #109. Please see the copyright section of the legal disclaimer (bottom of this page) for terms of use.

Last Update: 1 September 2019
21-Jun-2024 00:11 UT

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