Space

NASA working to fix Opportunity's memory

NASA working to fix Opportunit...
Artist's concept of the Opportunity rover (Image: NASA)
Artist's concept of the Opportunity rover (Image: NASA)
View 3 Images
Artist's concept of the Opportunity rover (Image: NASA)
1/3
Artist's concept of the Opportunity rover (Image: NASA)
Opportunity pauses on Endeavour Rim during its 25 mile trek on Mars (Image: NASA/JPL-Caltech)
2/3
Opportunity pauses on Endeavour Rim during its 25 mile trek on Mars (Image: NASA/JPL-Caltech)
Artist's concept of the Opportunity rover (Image: NASA)
3/3
Artist's concept of the Opportunity rover (Image: NASA)
View gallery - 3 images

NASA's Opportunity rover landed on Mars in 2004 and its 90-day mission has now lasted almost 11 years. Unfortunately, its age is beginning to show with the unmanned robotic explorer beginning to display signs of memory loss. Mission control at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, reports that Opportunity's computers have been resetting as its flash memory banks suffer fits of "amnesia," which engineers back on Earth are trying to repair.

Opportunity may be an extremely sophisticated piece of rolling scientific hardware, and it may be functioning a decade beyond its specifications, but its "brain" is still a computer relying on much the same components as any PC circa 2003. As anyone who uses computers on a regular basis knows, these components have a limited service life, which is why junk drawers inevitably fill up with dead tech. Worse, the Martian environment is extremely hostile to electronics, and microelectronics especially, because the incredibly dry, dusty climate generates static electric charges, and the thin atmosphere and almost non-existent magnetic field lets in dangerous levels of cosmic radiation.

Whether due to time or radiation, NASA says that Opportunity is now suffering from bouts of computer senility. Like most computers, the rover's uses a combination of volatile Random Access Memory (RAM), and a non-volatile memory – in this case, a set of seven flash memory banks. The latter are especially important because Opportunity is solar powered. This means that it can't spare the power to keep the RAM operating at night because the batteries are needed to keep the electronics warm, so data collected during the day is stored in the flash memory until it can be transmitted to Earth.

Opportunity pauses on Endeavour Rim during its 25 mile trek on Mars (Image: NASA/JPL-Caltech)
Opportunity pauses on Endeavour Rim during its 25 mile trek on Mars (Image: NASA/JPL-Caltech)

This arrangement has worked fine until now, but in recent weeks the flash memory has refused from time to time to record new data, causing the computers to reset like a cranky tablet. To prevent this from happening again and to avoid lost data, mission control tried re-formatting the flash memory, but with little success, so in early December it ordered Opportunity to carry out a more extensive repair, including using the RAM to collect data and transmitting it to Earth before sunset. However, the space agency says that the main problem has been located in one of the seven flash banks, which NASA plans to isolate.

"The mission can continue without storing data to flash memory, and instead store data in volatile RAM," says Mars Exploration Rover Project Manager John Callas of JPL. "While we're operating Opportunity in that mode, we are also working on an approach to make the flash memory usable again. We will be sure to give this approach exhaustive reviews before implementing those changes on the rover."

Launched on July 7, 2003, Opportunity is the twin of the now defunct Spirit rover. It landed on January 25, 2004, three weeks after Spirit, in the Meridiani Planum region of Mars for a mission scheduled to last 90 Martian days, but ten years later, it's still going strong. It continues to study Martian soil and provide surface calibration for orbital observations by the Mars Reconnaissance Orbiter, and has traversed over 25 miles (40 km).

Source: JPL

View gallery - 3 images
3 comments
David Earnest
When in starts wandering around in it's jammies and screaming profanities at random then we should worry. In the meantime it's safe to say Opportunity has exceeded expectations and deserves a raise.
Chester Dwag
A little out of the way for "percussive maintenance", otherwise NASA could send my grandpa out there with a ball peen hammer, a Budweiser, his encyclopedia of curses and let him do his thing.
Captain Danger
These guys can reformat and try to fix flash memory from a distance of 50 million miles? They are good. I wonder if they could take a look at a couple of computers I am having an issue with when they are done.