ITHACA, N.Y. – NASA’s Opportunity Mars rover now holds the off-Earth roving distance record after surpassing 25 miles (40 kilometers) of driving on the Red Planet since 2004. The previous record was held by the Soviet Union’s Lunokhod 2 rover.
A drive of 157 feet (48 meters) on July 27, 2014, put Opportunity’s total odometry at 25.01 miles (40.25 kilometers).This month’s driving brings the rover southward along the western rim of Endeavour Crater, which is 14 miles (22 kilometers) in diameter. Each day’s drive by Opportunity sets a new record for longest travel on wheels on a world other than Earth.
“Opportunity has driven farther than any other wheeled vehicle on another world,” said Mars Exploration Rover Project Manager John Callas, of NASA’s Jet Propulsion Laboratory (JPL), Pasadena, California. “This is so remarkable considering that Opportunity was intended to drive about one kilometer and was never designed for distance. But what is really important is not how many miles the rover has racked up, but how much exploration and discovery we have accomplished over that distance.”
Opportunity had driven more than 20 miles (32 kilometers) before arriving at Endeavour Crater in 2011. On this crater’s rim, it has examined outcrops containing clay and sulfate-bearing minerals. The sites are yielding information about ancient environments with milder water than the acidic, wet environment that left evidence Opportunity discovered at its landing site.
If the long-lived rover keeps working long enough to match the distance of a marathon footrace — 26.2 miles (about 42.2 kilometers) — it will be nearing the next major investigation site that the mission’s scientists have chosen: “Marathon Valley.” Observations from spacecraft orbiting Mars suggest several clay minerals are exposed close together there. The site is valley with steep slopes where the relationships among different layers may be evident.
The Lunokhod 2 rover, a successor to the first Lunokhod mission in 1970, landed on Earth’s moon on Jan. 15, 1973. Lunokhod 2 drove about 24.2 miles (39 kilometers) in less than five months (five lunar days). This total traverse distance has recently been established with the use of images from NASA’s Lunar Reconnaissance Orbiter (LRO) cameras showing Lunokhod 2′s wheel tracks.
Irina Karachevtseva at Moscow State University of Geodesy and Cartography’s Extraterrestrial Laboratory in Russia, Brad Jolliff of Washington University in St. Louis, Tim Parker of JPL and others collaborated to check that the map-based methods for computing traverse distances are comparable for Lunokhod-2 and Opportunity.
“The Lunokhod missions still stand as one of the signature accomplishments of what I think of as the first golden age of planetary exploration, the 1960s and ’70s,” said Steve Squyres of Cornell University, Ithaca, New York, principal investigator for NASA’s twin rovers, Opportunity and Spirit. “We’re in a second golden age now, and what we’ve tried to do on Mars with Spirit and Opportunity has been very much inspired by the accomplishments of the Lunokhod team on the moon so many years ago. It has been a real honor to follow in their historical wheel tracks.”
As Opportunity approached the 1973 mission’s mileage record earlier this year, the rover team chose the name Lunokhod 2 for a crater about 20 feet (6 meters) in diameter on the outer slope of Endeavour’s rim on Mars.
“I was part of the science team of both Lunokhod 1 and Lunokhod 2, and I know that rover missions require hard work with a high level of tension, “said Alexander Basilevsky of the Vernadsky Institute in Moscow, deputy leader of the science team for Lunokhod 2.” I would like to express my congratulations to the Opportunity team.”
The Mars Exploration Rover Project is one element of NASA’s ongoing and future Mars missions preparing for the journey to for a human mission in the 2030s. JPL manages the project for NASA’s Science Mission Directorate (SMD), in Washington. NASA’s Goddard Space Flight Center, in Greenbelt, Md., managers LRO for SMD.