No. 109 - Superior Conjunction Phase
22 January 2009 12:54
Report for Period 6 December 2008 to 16 January 2009
The 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.
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).
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.