After nearly two months at a standstill, NASA’s Mars rover Opportunity has driven its first tentative meters with a partially stowed robotic arm.

The rover rolled both backwards and forwards Jan. 19, repositioning itself at a new science target and testing its ability to drive with its instrument-laden robotic arm in an elbow-out position, mission managers said.

“It’s good to be driving again,” said Jim Erickson, rover project manager at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “It was sort of a combination between a test drive and going to an interesting target.”

Opportunity drove toward a rock named Overgaard, traveling about 2.4 meters in a ‘V’ shape with its robotic arm’s elbow jutting towards the front. The brief drive marked the rover’s first trip since late November 2005, when a broken wire in one of the shoulder joints for Opportunity’s arm prevented the appendage from deploying.

Rover handlers have spent that time conducting science observations and determining the best way to drive Opportunity with its arm only partially stowed. Opportunity and its robotic twin Spirit are designed to fold their respective robotic arms under their forward undercarriages for safe keeping during drives.

“So far it looks fine, but it will be awhile before we’re sure about that arm position,” Erickson said of the elbow-out stance. “We’ll be doing further analysis to see if there are other poses that are better for the arm.”

Opportunity will spend its time studying “Overgaard” along the rim of Erebus Crater for the next week or so before heading toward a new region of its Meridiani Planum landing site, mission managers said.

Steve Squyres, rover science team leader at Cornell University in Ithaca, N. Y. , said an outcrop dubbed Olympia and the more distant Victoria Crater are future targets for Opportunity’s science instruments.

Opportunity also will hit a mission milestone Jan. 25 when mission managers will celebrate the two Earth-year anniversary of the rover’s martian landing.

Meanwhile, the Spirit rover is continuing its trek toward an interesting patch of martian rock that mission scientists have called Home Plate after a brief pause to examine soil churned up by its wheels.

“We went through this soil and it was just white,” Squyres said , adding that the white-ish material appears to be a high concentration of ferric sulfate salts. “It was just too tempting to pass up.”

Spirit is currently about 300 meters from Home Plate and should reach it by March 11 at the latest in order to complete its science objectives before heading off toward McCool Hill in the distance, Erickson said.

Named after Columbia shuttle pilot William McCool, McCool Hill is part of the Columbia Hills chain at Spirit’s Gusev Crater landing site, named after NASA’s seven lost STS-107 astronauts. Spirit spent more than one year exploring nearby Husband Hill, with engineers planning to send the rover to the base of McCool by the onset of martian winter. The trip will allow Spirit to angle its solar arrays toward the Sun for optimum power generation.

“Really, all we need to do is get to get to the beginning of McCool Hill, because we can climb the hill in that position,” Erickson said.