No. 30 - Second Pointing Scenario
Several observations with the spacecraft slewing to extreme attitudes (for stray-light measurement) or scanning the sky in complex patterns were carried out. Several instruments participated in these simultaneous operations opportunities. Most of the activities took place outside coverage and were controlled by Mission Timeline commands uplinked offline. Data collected during the tests were dumped during the daily New Norcia passes. On 26 September a special MIRO test was conducted during the pass, but also controlled via on-board time-tagged commands.
In general the Pointing Scenario operations were conducted successfully. However some problems occurred that either lead to the need to repeat some of the observations or require more detailed analysis offline. These are the incorrect specification of the ALICE boresight offset, the incomplete commanding of the RPC LAP instrument during the "LAP dance" test, some error messages from VIRTIS and already known anomaly events from OSIRIS (front door opening failure, shutter error). The ALICE and RPC observations have been re-scheduled for 4 and 10 October respectively, and the PIs have submitted corrected inputs for the next attempt.
Navigation Camera images have been taken in parallel to the payload observations to support calibration activities. The Navigation Cameras have also been commanded in point target tracking mode over extended periods of time during slews. For the first time, on 30 September, a Camera image has been downlinked using the wavelet compression by SSMM.
Full daily passes over the New Norcia station were taken throughout the week. No DSN pass was taken this week, due to the intense pointing activities of the spacecraft outside New Norcia contacts.
The table below shows a chronology of the main activities in the reporting period:
|
Mission Day |
Date |
DOY |
Main Activity |
|
207 |
24/25.09.04 |
268/269 | Pointing: observations 11, 15, 29 |
|
208 |
25/26.09.04 |
269/270 | Pointing: observations 3, 22 |
|
209 |
26/27.09.04 |
270/271 | Pointing: observations 20, 27 |
|
210 |
27/28.09.04 |
271/272 | Pointing: observations 30, 28 |
|
211 |
28/29.09.04 |
272/273 | Pointing: observations 5, 6, 18, 31 + Alice special |
|
212 |
29/30.09.04 |
273/274 | Pointing: observation 32 |
|
213 |
30.09/01.10.04 |
274/275 | Pointing: observations 10, 26, 25 |
At the end of the last New Norcia pass in the reporting period (DOY 275) Rosetta was at 70.9 million km from the Earth. The one-way signal travel time was 3 minutes 56 seconds