No. 91 - Trajectory Correction for Asteroid Steins Flyby
A total of 12 New Norcia passes were taken during this reporting period. The tracking campaign with the Deep Space Network (DSN) stations was completed on DoY 329. Some of the passes between 19 and 25 November have been used for TM/TC activities as well.
| DOY | Date | Pass | Main Activity |
| 321 | 17/11/07 | DSS-25 1359 | Tracking Pass |
| NNO 1359 | Science data downlink | ||
| 322 | 18/11/07 | DSS-26 1360 | Tracking Pass |
| NNO 1360 | Science data downlink | ||
| 323 | 19/11/07 | DSS-15 1361 | Science data downlink |
| NNO 1361 | Tracking Pass | ||
| 324 | 20/11/07 | DSS-26 1362 | Science data downlink |
| NNO 1362 | Tracking Pass | ||
| 325 | 21/11/07 | DSS-26 1363 | Science data downlink and NAVCAM B test |
| NNO 1363 | Tracking Pass | ||
| 326 | 22/11/07 | DSS-15 1364 | Tracking Pass |
| NNO 1364 | Trajectory correction manoeuvre | ||
| 327 | 23/11/07 | DSS-26 1365 | Monitor and NAVCAM B test |
| NNO 1365 | Tracking Pass | ||
| 328 | 24/11/07 | DSS-26 1366 | Tracking Pass |
| 329 | 25/11/07 | DSS-25 1367 | Tracking Pass |
| 330 | 26/11/07 | NNO 1368 | AOCS Checkout 7 |
| 331 | 27/11/07 | NNO 1369 | AOCS Checkout 7 Reaction wheels stiction test |
| 332 | 28/11/07 | NNO 1370 | Monitor |
| 333 | 29/11/07 | NNO 1371 | Tracking Pass |
| 334 | 30/11/07 | NNO 1372 | Tracking Pass |
At the end of the reporting period (DoY 334) Rosetta was at 13.1 million km from Earth (0.088 AU) and the one-way signal travel time was 44 seconds. The distance to the Sun was 139.5 million km (0.93 AU).
Trajectory Correction Manoeuvre
A trajectory correction manoeuvre was executed on 23 November, 00.54 UT, in order to set the proper trajectory for the close encounter with asteroid Steins planned for September 2008. The manoeuvre was executed using accelerometers, and lasted 538 seconds (the time that Rosetta was in Orbit Correction Mode). The commanded Delta-V was 1.5269 ms-1 and the executed Delta-V (as read in spacecraft telemetry) was 1.526107
The second leg of this correction manoeuvre will be executed in February 2008.
Spacecraft
Payload
During the reporting period some of the instruments have been operating in the final part of the second Earth swing-by observation campaign.
ALICE
The instrument was operated till DoY 321, 16.10 UT.
CONSERT
The instrument is OFF.
COSIMA
The instrument is OFF.
GIADA
The instrument is OFF.
MIDAS
The instrument is OFF.
MIRO
The instrument was operated several times during the Earth swing-by campaign and completed its activities on DoY 322, 12.15 UT.
OSIRIS
The instrument is OFF.
ROSINA
Instrument is ON (with ROSINA's RTOF sensor in stand-by) as part of an out-gassing attempt. The instrument was powered OFF between DoY 331, 21.35 UT, and DoY 332, 03.30 UT, during the reaction wheels (RWs) stiction test.
RPC
The instrument completed its Earth Swing-by operations on DoY 324, 14.00 UT.
RSI
The instrument is in muted status.
VIRTIS
The instrument is OFF.
LANDER Philae
The ROMAP instrument completed its operations on DoY 324, 14.10 UT.
SREM
Since DoY 248 the accumulation settings of the Standard Radiation Environment Monitor are configured for active cruise mode.
Future Milestones
The Earth swing-by phase is now completed and the spacecraft will enter a quiet period. During the next reporting period some tests with the navigation cameras will be performed to prepare for the optical navigation campaign required for the asteroid Steins approach phase next year. The relatively quiet period will also be taken as an opportunity to characterise the solar torques on the spacecraft and some recovery activities on the MIDAS instrument.