No. 105 - Gravitational Microlensing Observations
23 September 2008 12:51
Report for Period 6 September to 19 September 2008
The reporting period covers the two weeks of post-asteroid fly-by activities mainly dedicated to the downlink of science data. All science data acquired during the asteroid fly-by phase have been successfully retrieved on ground and operations are now continuing with the OSIRIS observations of gravitational microlensing events.
Mission operations were conducted with the support of the ESA New Norcia (NNO) ground station and with NASA DSN ground stations (DSS).
At the end of the reporting period (DoY 263) Rosetta was at 386.1 million km from Earth (2.58 AU) and the one-way signal travel time was 1288 seconds. The distance to the Sun was 324.1 million km (2.16 AU).
The fly-by operations are now completed and the OSIRIS observations of gravitational microlensing events will be completed by 5 October. The spacecraft will then continue its fourth orbit around the Sun reaching aphelion on 17 December 2008 at a distance of 2.26 AU. It then heads back to Earth for the mission's last gravity assist and third Earth swing-by on 13 November 2009.
The angular separation between the spacecraft and the Sun will stay below 3° (conjunction) between 17 December 2008 and 6 January 2009 with the minimum angular separation (1.6°) on 28 December. No special activities are planned for this conjunction phase during which short weekly passes will be taken.