Mars Express Status Report - November 2005
During ground station testing, a safe mode occurred on Thursday 22 September, which led to a limited loss of science observations. A quick recovery was achieved by ESOC, and the spacecraft returned to nominal operations. An orbit correction manoeuvre was performed in order to remove the perturbation effects of the safe mode on the orbit and to bring the spacecraft back to the nominal free-drift orbit. The reason for the safe mode is understood and procedures have been updated to prevent it from happening again. At the end of November, an orbit correction manoeuvre will be performed in order to return from the current free-drift orbit to a frozen orbit; the main advantage being the fixed guaranteed overlap of adjacent HRSC ground tracks.
Operations and archiving
Science operations are proceeding well. Given the current small distance to Mars and the favourable illumination conditions, the last three months saw the return of unprecedented amounts of science data from Mars Express.
The third eclipse season started on 3 October and spacecraft resource constraints will considerably limit the amount of science return possible. The planning of payload activities has been done accordingly, the priority being given to the imaging instruments HRSC and OMEGA until the illumination conditions become less favourable for these two instruments. As a consequence, the science operations of PFS, MARSIS and ASPERA will be severely impacted by the power limitations. During the next eclipse season (4th quarter of 2006), which coincides with Mars being at a large distance to the Sun, it will be very difficult to maintain a very active science programme. Preparations to try and improve this situation are underway.
A slow, but steady, stream of data continues to populate the Mars Express archive.
The August 2005 issue of Planetary and Space Science (Volume 53, Issue 10) was dedicated to PFS and contained 12 papers on PFS results. A special edition of ICARUS dedicated to results from ASPERA is in preparation. A paper by Pätzold et al. on Radio Science observations of a 3rd layer in the Martian ionosphere has been published in Science.
Initial science results from the MARSIS radar on the ionospheric and subsurface measurements are very interesting. Two papers have been accepted in the journal Science.