Mars Express Status Report - November 2009
During this reporting period mission performance has been good, with an average of 1.7 science pointings and 4.9 observations per orbit. There were 105 orbits with pericentre passages in November, corresponding to the operations medium term plans MTP-71 and MTP-72.
|Spacecraft distance to Earth||177 million km||142 million km|
|One-way signal travel time||9m 51s||7m 53s|
|Sun elevation at pericentre||+35°||+26°|
The instruments performed nominally during the reporting period. As part of the routine operations all instruments were operated regularly: ASPERA on 96% of the orbits, HRSC on 68%, MARSIS on 85%, OMEGA on 26%, PFS on 72%, and SPICAM on 100% of the orbits. Also 10 VMC observations were performed. Overall, for all instruments, 98.8% of the planned observations were executed successfully. The daily amount of returned science data was 2.3 Gbit.
The software patch that was uplinked last month to improve the performance of ASPERA is now being used operationally, with good results.
Spacecraft status and performance
Thermal and Power sub-systems
Both sub-systems are performing nominally. Boost heating has been applied for 1 hour immediately prior to eclipse entry to reduce the heater demand during the eclipses in the eclipse season. Outside of the observation pointings and the Earth pointings a 'warm-up' attitude has been adopted for the spacecraft to reduce heater demand. This has the added benefit of reducing torques due to Solar dynamic pressure, thus reducing fuel consumption during the regular wheel off-loadings.
Telemetry, Tracking & Command (TT&C)
The TT&C sub-system is performing nominally. The telemetry bit rate was 228 kbps (maximum) over all ground stations throughout the reporting period.
Radio science investigations using the spacecraft's radio links took place on 13 occasions, as part of the Mars Radio Science experiment (MaRS). Due to power constraints during the current eclipse season the experiments have been suspended from MTP-72 until MTP-75.
Ground segment status and performance
Mars Express operations were supported by ground stations from the ESA tracking station network (ESTRACK) and the NASA Deep Space Network (DSN).
The number of tracks was on average 21 per week, with 26 passes over New Norcia (ESTRACK), 22 over Cebreros (ESTRACK), and 37 over Goldstone (DSN). More than 98.9% of the data available on-board the spacecraft has been received on ground.
The Chinese VLBI Network successfully tracked Mars Express on 10-11 November 2009.
- 30 January 2010: Low-gain antenna (LGA) characterisation
- 3 March 2010: Phobos closest ever approach (at 62 km from the moon's centre and 50 km from its surface)
- March 2010: Orbit change to 88:25 resonance
- 19 April 2010: End of 8th eclipse season (started on 10 November 2009)
- 15 August 2010: End of 8th occultation season (started 20 September 2009)