Only 11 years and two months after it began, NASA’s Mars Opportunity rover has completed a marathon across the planet’s barren red desert. The rover made its final roll toward the 26.219-mile mark Tuesday morning, logging in a total of 26.221 miles (42.195 kilometers) on its odometer.
“It’s historic,” said John Callas, a NASA astronomer who manages the Mars Exploration Rover project, in an interview. “This is the first time any human enterprise has exceeded a marathon somewhere other than Earth.”
Opportunity was designed to drive a distance of only one kilometer. Its current record is 42 times longer than that. “It’s like having a car that’s supposed to last 100,000 miles, and then you drive it 4 million miles without ever changing its oil—that’s just amazing!” Callas said. For the past few months he and his colleagues have been counting down the distance on an office whiteboard. The final leg of the race, about 140 feet, is an entry they now feel lucky to erase.
“We’re well past our warranty on this rover,” said Callas. “The thing we live with every day is that the rover can die tomorrow.”
And there are many things that can go wrong with a robot that’s past its prime. For instance, the team thought the wheels would wear out, a problem that helped decommission Spirit, its twin rover, seven kilometers into its mission. Even Opportunity’s final push did not come without its hurdles. Days before the golf-cart-sized vehicle began the last part of this journey, Callas and his team had to reformat its flash memory, a portion of which was becoming corrupted and causing episodes of “amnesia.” For three months Opportunity operated without its flash memory, which normally stores crucial operating data that the rover can utilize whenever it’s powered up. The fix included recreating part of the rover’s software, a task Callas likened to reprogramming your computer’s operating system while it’s 140 million miles away.