The Mars Odyssey orbiter placed itself into a precautionary safe mode on December 26 while remaining in communication with Earth. This is not the first time that the long-serving spacecraft has encountered this issue.
Odyssey, which has been orbiting Mars since 2001, is currently the oldest spacecraft in service above the Red Planet. According to a NASA press release, the Odyssey project team determined that the spacecraft entered into the safe mode in response to “an uncertainty aboard the spacecraft about its orientation with regard to the Earth and the Sun”. The project team is working to restore the orbiter to full operation.
A reset of the craft’s inertial measurement unit and a circuit card that acts as an interface between that sensor, the flight software, and the star tracker restored the orbiter’s knowledge of its orientation. A similar fault and solution occurred in December of 2013, after which Odyssey was able to resume normal mission operations.
In addition to its own observation and science tasks, the Mars Odyssey spacecraft has been serving as a communications relay for ongoing surface missions on Mars, including the Opportunity and Curiosity rovers.
The project team expects communication relay services to resume this week, with Odyssey expected to resume its own science investigations by next week.
Mars Odyssey was launched on April 7, 2001, atop a Delta II 7925-9.5 rocket from Cape Canaveral Air Force Station’s Space Launch Complex 17A located in Florida.
Since December of 2010, it has been the longest continuously-operated robotic mission at Mars. The mission is managed by NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California and was built by Lockheed Martin Space Systems in Denver, Colorado.