No. 80 - Deep Space Manoeuvre 3
14 May 2007 16:13Report for Period 21 April to 11 May 2007
The reporting period covers a period of three weeks of limited science observations and navigation after the successful execution of the deep space manoeuvre 3. The Jupiter observation campaign with the ALICE instrument continued till beginning of May.
A recovery activity for the Lander instrument MUPUS (MUlti-PUrpose Sensors for Surface and Sub-Surface Science) failed and will be re-attempted before the Near Sun Hibernation phase. The Lander Radio Frequency (RF) test was conducted according to the plan.
The AOCS check-out number 6 has been conducted according to the plan. Data are being analysed.
A total of 20 New Norcia passes (8x4h tracking only) were taken during this period.
At the end of the reporting period (DOY 131) Rosetta was at 251.5 million km from Earth (1.68 AU; one-way signal travel time was 13 minutes 59 seconds). The distance to the Sun was 236.9 million km (1.58 AU).
Deep Space Manoeuvre 3
The Rosetta Deep Space Manoeuvre 3 was executed at 22:04 UT on 26 April with a fuel consumption of ~6.96 kg. It had a nominal magnitude of 6.526 ms-1.
Subsequent evaluation of the orbit determination results on 2 May show that the manoeuvre performance was very good, with a slight over-performance of 0.65% (+42 mms-1) estimated with a 1-sigma uncertainty of 0.18% (12 mms-1).
For the direction, the component along the body X-axis was extremely close to that predicted: this component of the direction error was only a tiny fraction of a degree with a 1-sigma uncertainty about the same as the error estimate itself. The estimate for the Y-component of the direction error is about 0.5° with a 1-sigma uncertainty of about 0.2°.
The reporting period included the following activities:
The Mars Swing-by Phase will be formally completed on 29 May after the completion of the navigation campaign following the Deep Space Manoeuvre 3.
The Payload Check-out 5 (passive) will be completed by 23 May. This activity will be followed by a change of guidance reference and by the entry into Near Sun Hibernation Mode at the beginning of June.