The NASA Mars Reconnaissance Orbiter (MRO) is going to be on a bit of a vacation from its science mission and relay operations while engineers on Earth conduct maintenance. The maintenance work is expected to last about two weeks. During that time, other orbiters will continue relaying data from the surface of Mars for the Curiosity rover and Mars InSight lander.
The maintenance work that NASA will undertake involves updating the battery parameters in the flash memory of the orbiter. In the entire 15-year history of the MRO, such maintenance work has only been done twice before. NASA needs to apply the update because the space agency recently determined that the battery parameters in the flash memory or out of date, and if used, would be unable to charge the batteries on MRO to desired levels.
Along with updating the battery parameters, engineers will also use the downtime to update planetary position tables that also reside in the flash memory. As part of the maintenance, MRO will be placed into a precautionary standby mode known as “safe mode” three times over the course of the update. The orbiter will also swap from its primary computer called Side-A computer to the redundant computer called Side-B computer.
The MRO launched in 2005 and has been on station orbiting the Red Planet since March 10, 2006. During its mission, the MRO has returned 371 terabits of data. NASA notes that spacecraft that remain in space for long periods have to guard against failures due to aging hardware and the effects of the harsh space environment. The backup computer is one of the redundancies that NASA built into the MRO, and builds and other spacecraft, to help maintain mission performance in the event of an issue.
To keep both computers on the MRO up-to-date, engineers will update the flash on the Side-A computer first and then command it to reboot to ensure that the flash memory was properly updated. Once the update has been confirmed, engineers will swap to Side-B and repeat the process. Once the upgrades are done, MRO will be returned to its science and relay-support activities. NASA says that after the update is applied, the spacecraft will be ready to continue operations well into the next decade.