Anomalies in the operation of the solid-state mass memory system on board Mars Express have caused science observations to be temporarily halted. A technical work-around is being investigated that will enable the resumption of a number of observations and should evolve into a long-term solution.
In mid-August, Mars Express autonomously entered safe mode, an operational mode designed to safeguard both the spacecraft itself and its instrument payload in the event of faults or errors.
The cause of entering the safe mode was a complex combination of events relating to reading from and writing to memory modules in the Solid-State Mass Memory (SSMM) system. This is used to store data acquired by the instruments and housekeeping data from the spacecraft's subsystems, prior to its transmission to Earth, and is also used to store commands for the spacecraft that have been received from the ground stations, while awaiting execution.