NASA’s Mars Reconnaissance Orbiter (MRO) made an unscheduled computer swap on March 9, forcing the mission into a temporary “safe mode,” report mission managers at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. The cause of the glitch is a mystery, but the mission’s ground team are currently restoring the spacecraft to full operations.
The glitch not only suspended orbital science operations, but it also suspended communication relay services for NASA’s two Mars rovers, Opportunity and Curiosity. Both rover missions are now using NASA’s veteran Mars Odyssey satellite as a relay satellite. The MRO carries six science payloads including the famous High-Resolution Imaging Science Experiment (HiRISE) camera that has been observing the red planet at an unparallelled resolution.
“The spacecraft is healthy, in communication and fully powered,” said JPL’s Dan Johnston, MRO Project Manager. “We have stepped up the communication data rate, and we plan to have the spacecraft back to full operations within a few days.”
The MRO has experienced four unexpected computer swap events that have triggered safe modes since it arrived at Mars orbit in 2006 — the last such event occurred in November 2011. A safe mode in any robotic space mission is an automatic safeguard that has been put in place when an unexpected condition arises within an electrical or computer system. The MRO has had many other safe modes not triggered by computer swaps, often caused by power spikes triggered by suspected high-energy cosmic rays.
The MRO has two computer systems — an “A” side and a “B” side — where one side acts as a back-up should the other side fail. It appears that the MRO spontaneously swapped sides, hence why the safe mode was triggered, reducing the chances of permanent damage.
However, this particular event was unique in that the swap also included a redundant radio transponder on the orbiter. Engineers are continuing to leave the redundant transponder in a powered-up state while they investigate the situation with the now out-of-service primary transponder.
While JPL scientists and engineers are working hard to resume science operations, they will no doubt be concerned about this latest glitch and will continue to investigate the event.