Science

Memory Issues Unresolved, Mars Rover Opportunity To Rely On RAM

NASA’s Mars rover Opportunity has been dealing with a nagging flash memory glitch for more than nine months now. The bad news is that the software engineers have been unable to get a handle on the memory problem despite multiple reformats, but the good news is the rover can continue to function in persistent RAM mode. In fact, Opportunity did just that for a few months in late 2014 when the flash memory glitch was first noticed.

Memory Issues Unresolved, Mars Rover Opportunity To Rely On RAM

According to Bill Nelson, chief of MER engineering at NASA’s Jet Propulsion Laboratory (JPL), the rover will be operating in persistent RAM mode for the time being. “We will stay in persistent RAM mode for the foreseeable future while we continue to investigate the sudden reboots or warm resets and amnesia events that have been occurring and which we attribute to Opportunity’s flash or long-term memory,” Nelson said.

Operating Mars Rover Opportunity on persistent RAM

“While it is inconvenient not to have flash, its not a big impact on the mission,” noted John Callas, MER project manager at JPL. “It kind of like being a grad student who goes to the all-you-can to buffet, loads up, and then brings food back to the refrigerator in dorm room to eat later,” he said metaphorically speaking. “For now, we don’t have a ‘refrigerator,’ so we have to eat it or throw it out. However, we have shown that we can operate in persistent RAM mode and still have a very productive science mission.”

Top NASA engineers working on flash memory problem

Of note, the effort to figure out Mars rover Opportunity’s flash memory problem involves some of the best software engineers from across the globe. Several ex-MER engineers who worked on the electronics and software programming of Mars rovers Spirit and Opportunity began consulting a couple of months ago with current engineers on a “flash tiger team” led by MER Flight Director Bekah Sosland to further investigate the rover’s flash memory problems.

“We may take ‘toe-dips’ back into using flash periodically to see what the rover tells us, but for now we’re trying to see if we can learn more about what’s going on,” noted MER engineering head Nelson, who is also a member of the flash investigation team.