Although the engineers identified the problem and programmatically fixed Opportunity’s “bout of amnesia”, NASA’s aging rover continued to suffer from memory problems.
“We changed the way the rover uses flash memory to try to correct rover-tested problems,” said John Callas, project manager at Opportunity from Jet Propulsion Laboratory at NASA, Pasadena, California, during a press release. "Although we are a little disappointed that the attack of amnesia happened only five days after reformatting, but we are not surprised. It is still not clear what the root cause of the malfunction. Only time will tell us to mitigate the most serious flash memory problems."
The problem, we think, was centered around one of the seven memory banks in Opportunity flash memory - a kind of “hard disk” on board the spacecraft, the data on which is stored even when the power supply to the rover is reduced. More precisely, do not get lost. A telemetry mission can be stored when the rover is turned off to conserve battery power during the Martian night. But at the end of last year, the spacecraft somehow “forgot” valuable data due to a damaged data memory bank. As a result, arbitrary discharges occurred during the day. This obstacle in the progress of the mission prompted the engineers to turn off the flash photography mode so that Opportunity would avoid using its flash memory, and instead temporarily stored the data in the volatile (operational) memory and regularly transferred them to Earth, before it was idle. As RAM on your PC or Mac, volatile memory only provides temporary data storage, clearing when the power of the rover is reduced.
On March 20, engineers reformatted the memory of the Opportunity device in order to avoid using the 7th bank of flash memory after updating the software. Although at the present time the rover does not show the worst symptoms of amnesia, it seems that its memory problems are far from being resolved.