19 Nov 2004
(Source: European Space Agency)
Preparations for Trajectory Correction Manoeuvre 4
European Space Agency
November 19, 2004
Report for period 28 October to 19 November 2004
Rosetta continues to fly in cruise mode which it entered 17 October. The AOCS gyro-less estimator was activated on 4 November and has been running since, outside the control loop for validation. This activity required an AOCMS patch in RAM to prevent incorrect use of gyro-less estimator output by the FDIR when the gyro-less and gyro-stellar estimators are ON in parallel. So far, the performance of the gyro-less estimator is good.
The last pass of the reporting period was dedicated to the preparation of TCM-4. In particular, the slews around the manoeuver have been loaded on-board. This small Trajectory Correction Manoeuver of about 9 cms-1 is planned on 25 November. SREM is kept activated for background radiation monitoring since 22 October. Weekly passes over the New Norcia station have been made since 18 October. There is no DSN support during this phase.
The table below shows a chronology of the main activities in the reporting period:
Mission Date DOY Main Activity
241 28/29.10.04 302 Monitoring pass
248 04/05.11.04 309 Monitoring pass - Gyro-less estimator switch-on
255 11/12.11.04 316 Monitoring pass
262 18/19.11.04 323 Monitoring pass - TCM-4 Preparation
Note: skipped passes are not included.
At the end of the last New Norcia pass in the reporting period (DOY 324) Rosetta was at 49.8 million kilometres from the Earth. The one-way signal travel time was 2 minutes 46 seconds.