PASADENA, Calif. -- The Spirit Mars rover sits atop its landing platform and has made one small step toward a giant leap onto the surface of the Red Planet. Engineers have passed a key hurdle in preparing the large robot for its first traverse across its landing site -- Gusev Crater.

The Mini-TES instrument is churning out quality data, measuring temperatures given off by the martian rocks and fine grain sand. Strong temperature differences have been seen at a site called "Sleepy Hollow", not too distant from where Spirit rests.

By far the most intriguing first result is the detection of carbonate by Mini-TES. Carbonate minerals, such as limestone, can form from chemical reactions that pull carbon dioxide out of the atmosphere into bodies of water.

In addition, the Mini-TES is measuring the carbon dioxide resident in Mars atmosphere, data that will be of benefit to atmospheric scientists.

"We came looking for carbonate," said Phil Christensen, Payload Element Lead for the Mini-TES at Arizona State University in Tempe.

"Weve got a long way to go to understand the carbonate," Christensen said, but added a note of caution.

Still to be sorted out is how much carbonate is carried in wind blown dust contrasted to the substance being truly intrinsic to Gusev Crater. That knowledge is part of Spirits mission to learn how long the environment there stayed wet and if, indeed, Gusev was once covered by a lake.

Previously, the orbiting Mars Global Surveyor had found carbonates in dust at several locations on the surface. Scientists think the carbonates were created in the presence of water, but they are not yet certain.

Once mobile, Spirit has the ability to approach the rim of an impact craterto look with Mini-TES for carbonate down in the crater, said Steve Squyres, Principal Investigator of the Mars Exploration Rovers from Cornell University.

"I think were going to be chasing this carbonate story for weeks and months," Squyres said.

"We are beginning to develop a familiarity with Mars," Christensen said. "But the beauty is that it is not the Earth. Its not Arizona desert. There are details and subtleties. It is a remarkably strange place. Were just scratching the surface of what its going to be like," he added.

Engineers are moving forward in getting Spirit prepped for rolling off the landing platform. That milestone may now occur early next week.

There was good news on getting Spirit delivered to the surface of Mars. A delicate process to stand the robot on its landing deck was successful yesterday, but more steps are to come before the robot is free to wheel across the martian terrain.

"This is not a $400 million rover. It is a priceless assetit is absolutely priceless," said Peter Theisinger, Mars Exploration Rover project manager. Spirit is fully functioning and sitting in a beautiful scientific target, he said

Theisinger said that Spirits handlers are not going to take any inappropriate risks. "We are proceeding in a measured, tempered way."

Increased attention is being paid, Theisinger said, in preparing for the next rover landing, Opportunity. This identical robot will plow into Mars atmosphere on January 24 at about 9:05 p.m. Pacific Standard Time.

This second lander is headed for Meridiani Planum, a smooth plain near the equator halfway around the planet from where Spirit now sits.

At Opportunitys landing zone, dust particles have subsided, but still linger in the area caused by dust storm activity elsewhere on the planet.

"Things are breaking in our direction. Its well within the knobs and levers we have," Theisinger noted in detailing Opportunitys upcoming landing.

Upwards of 60 people are now involved in reconstructing Spirits entry, descent, and landing. That information is being fed into possible software changes, entry angle of Opportunity, and the timing of the crafts critical parachute deployment.

"We have a tremendous amount of good data from Spirit," Theisinger told SPACE.com .

At this point, engineers here dont have any contentious issues. A missing key part of playback data during Spirits plunge through the martian atmosphere was finally available to planners a few days ago, he said.

"Thatll tie things together," Theisinger concluded.

• SPACE.com's Complete Coverage of Mars Express, Spirit and Opportunity

• Launch and Mission Operations News from SPACE.com

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