Mars Rover Opportunity Gets Memory Fix Ahead of Marathon Milestone
This false-color view captured by NASA's Opportunity Mars rover shows part of Marathon Valley as seen from an overlook to the north. The image was taken by the rover's Pancam on March 13, 2015.
Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.

Engineers have troubleshot the memory issue affecting NASA's Opportunity Mars rover, just in time for the long-lived robot to complete its Red Planet marathon.

A software upgrade has restored the use of Opportunity's flash memory — the kind that can store data even when the power is off — NASA officials announced Monday (March 23). The Opportunity rover had been doing without flash memory since late 2014 in the wake of a glitch.

"Opportunity can work productively without use of flash memory, as we have shown for the past three months, but with flash we have more flexibility for operations," Opportunity Project Manager John Callas, of NASA's Jet Propulsion Laboratory in Pasadena, California, said in a statement. "The rover can collect more data than can be returned to Earth on any one day. The flash memory allows data from intensive science activities to be returned over several days."

Analysis of Opportunity's memory issues led engineers to conclude that some of the problems lay in one of its seven "banks" of onboard flash memory. The software upgrade allows the rover to bypass this bank, known as Bank 7, NASA officials said.

This map shows the progress NASA's Mars Rover Opportunity is making toward reaching a driving distance equivalent to a marathon footrace — 26.219 miles, or 42.195 kilometers.
This map shows the progress NASA's Mars Rover Opportunity is making toward reaching a driving distance equivalent to a marathon footrace — 26.219 miles, or 42.195 kilometers.
Credit: NASA/JPL-Caltech/Univ. of Arizona

The fix comes as Opportunity nears 26.219 miles (42.195 kilometers) of Red Planet driving — the length of a marathon race here on Earth. As of Monday, the rover was just 47 yards (43 meters) shy of that milestone, which it should reach when it enters a location dubbed Marathon Valley.

But Opportunity is not in any hurry to cross the finish line: The rover will observe and investigate a crater named Spirit of St. Louis before cruising into Marathon Valley, NASA officials said.

Opportunity landed on Mars in January 2004, a few weeks after its twin, Spirit. Both golf-cart-size robots were tasked with three-month missions to search for evidence of past water activity on the Red Planet.

Spirit and Opportunity succeeded in this goal, gathering data that has reshaped scientists' understanding of Mars' past. And they kept on driving for years after their warranties expired: Spirit stopped communicating with Earth in 2010, and Opportunity is still going strong.

Opportunity already holds the distance record for off-planet driving. In second place is the Soviet Union's Lunokhod 2 rover, which traveled 24.2 miles (39 km) on the moon in 1973.

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