No. 87 - Ongoing Payload Checkout
| DOY | Date | Pass | Main Activity |
| 275 | 02/10/07 | NNO 1312 | Tracking Pass |
| 276 | 03/10/07 | NNO 1313 | Tracking Pass |
| 277 | 04/10/07 | NNO 1314 | "Close to Sun"configuration and SSMM clean-up |
| 283 | 10/10/07 | NNO 1320 | RSI PC6 activities |
| 284 | 11/10/07 | NNO 1321 | Data downlink, MIDAS Health check |
At the end of the reporting period (DOY 285) Rosetta was at 29 million km from Earth (0.19 AU; one-way signal travel time was 1 minute and 37 seconds). The distance to the Sun was 175.6 million km (1.17 AU).
Spacecraft
Payload
During the reporting period limited activities have been conducted with the payload complement.
ALICE
Instrument is OFF
CONSERT
Instrument is OFF
COSIMA
Instrument is OFF
GIADA
Instrument is OFF
MIDAS
As part of anomaly investigation MIDAS has been activated twice (DoY 277 and 283) in the reporting period for a health check. In both cases proper functioning of the instrument could be proved.
MIRO
Instrument is OFF
OSIRIS
Instrument is OFF. Activities will be conducted in the next reporting period as part of anomaly investigation.
ROSINA
Instrument is ON (RTOF in stand-by) as part of an out-gassing attempt.
RPC
Instrument is OFF.
RSI
RSI PC6 activities have been executed on DoY 283. From a spacecraft point of view all activities have been nominally executed.
VIRTIS
Instrument is OFF.
LANDER Philae
Instrument is OFF.
SREM
Since DoY 248/2007 the accumulation settings are configured for active cruise mode.
Future Milestones
The preparation of the Earth Swing-by phase is proceeding according to the plan. Latest orbit determination indicates that a trajectory correction manoeuvre will be very likely needed at on the 18th of October. The swing-by manoeuvre will take place on the 13th of November at 20:57 UTC.
Earth Swing-by 2 Targeting
On the plot below, the blue cross and surrounding 3-sigma error ellipse were the estimates for the location in the Rosetta B-plane, corresponding to the 2nd Earth swing-by, that were made on the basis of a short arc solution using data from the time of NSHM exit up to 19 September.
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From a longer arc orbit determination using data acquired since exiting NSHM and up to the end of the pass on 04 October, and a subsequent orbit prediction, the red cross and surrounding 3-sigma error ellipse shows the current estimate in the B-plane. This estimate is 68 km from the target.
The target location corresponds to a perigee altitude of 5299 km (relative to the Earth's equatorial radius). The estimate corresponds to an altitude of 5364 km with a 3-sigma uncertainty of 39 km.
The estimated time of closest approach (perigee passage) is 20:57:23 UTC on 13 November (the same as the previous estimate). The 3-sigma uncertainty is now 7 seconds. Based on the present solution, a manoeuvre at arrival minus 4 weeks, on 18 October, would have a delta-V of about 4 cm per second.
