NASA’s Mars Reconnaissance Orbiter put itself into a safe mode Wednesday morning, Aug. 26, for the fourth time this year. While in safe mode, the spacecraft can communicate normally with Earth, but aborts its scheduled activities, and awaits further instructions from ground controllers. “We hope to gain a better understanding of what is triggering these events and then have the spacecraft safely resume its study of Mars by next week,” said MRO Project Manager Jim Erickson.
Engineers have begun the process of diagnosing the problem prior to restoring the orbiter to normal science operations, a process expected to take several days. They will watch for engineering data from the spacecraft that might aid in identifying the cause of event and possibly of previous ones.
A possible cause for the frequent anomalies is cosmic ray hits. But the spacecraft has reacted differently with the various safe mode entries. The orbiter spontaneously rebooted its computer Wednesday, as it did in February and June, but did not switch to a redundant computer, as it did in early August.
To help in investigating a root cause of the three previous anomalies, engineers had programmed the spacecraft to frequently record engineering data onto non-volatile memory. That could give an improved record of spacecraft events leading up to the reboot.
MRO has been in Mars orbit since 2006, and has returned more data than all other current and past Mars missions combined.