http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=35642

Monitoring New Avionics Software
European Space Agency
Rosetta
02 Aug 2004

Report for week 23 July to 30 July 2004

In the reporting period the spacecraft was monitored daily to ensure the correct behaviour of its avionics systems after the upload and activation of the new version 7 of the on-board software.

Taking the opportunity of this period of daily contact a number of tests were carried out, which in turn served as confidence checks of the functionality of the new software:

• he two Navigation Cameras were checked out on 25 July and the first pictures received showed the Earth-Moon system from a distance of 70 million km
• for the first time the new strategy for reaction wheel offloading in an optimized attitude was used on 27 July, to reduce fuel consumption in high disturbance torques conditions
• the redundant Transfer Frame Generator (TFG) and Decoder were tested as part of the redundancy commissioning
• a special Star Tracker test was carried out on 29 July to track stars which have been identified for elimination from the catalogue
• a new thermal characterization exercise was carried out on 29 July, to observe the thermal behaviour of the spacecraft when the Sun is shining on the ?Z side with an inclination of 50 degrees over the +X axis

The TC files containing the patch commands for the redundant avionics processors have been uplinked to the on-board mass memory. The patch of the redundant processors to the new software version 7 is planned for the beginning of August.

The table below shows a chronology of the main activities in the reporting period:

Mission Date DOY Main Activity
Day
144 23/24.07.04 205/206 Monitoring pass, uplink weekly MTL
145 24/25.07.04 206/207 Monitoring pass
146 25/26.07.04 207/208 NAVCAM commissioning
147 26/27.07.04 208/209 Load PM2 v7 TC files to SSMM
148 27/28.07.04 209/210 Load PM3 v7 TC files to SSMM
149 28/29.07.04 210/211 TFG redundancy switching test
150 29/30.07.04 211/212 STR catalogue test, thermal characterization ?50?, Decoder redundancy switching test
At the end of the last New Norcia pass in the reporting period (DOY 212) Rosetta was at 71.9 million kilometres from the Earth. The one-way signal travel time was 3 minutes 59 seconds.