Opportunity travels 12 miles in 74 months

PASADENA, Calif., March 25 (UPI) -- NASA scientists say the Mars Exploration Rover Opportunity has surpassed 12.4 miles (20 kilometers) of total driving since it landed on Mars Jan. 25, 2004.

On a Wednesday drive that occurred on the 2,191st martian day, or sol, of the mission, the rover covered 220 feet southward as part of its long-term trek toward Endeavour Crater to the southeast, the space agency said.

To reach Endeavour, the aging rover will need to drive about 7.5 miles (12 kilometers) farther.

NASA said Opportunity's initial mission on Mars was originally planned to last three months with a driving-distance goal of less than half a mile.

"Meanwhile, Spirit, Opportunity's twin, is continuing minimal operations due to declining solar energy with the approach of winter in Mars' southern hemisphere," NASA said in a statement. "Spirit has been communicating on schedule once per week. It is expected to drop to a low-power hibernation mode soon that could prevent communications for weeks at a time during the next several months."

Both rovers are managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif.