NASA alters rover schedule

PASADENA, Calif. -- NASA on Monday released the first 360-degree color panorama of the terrain on Mars that its Spirit rover should roll onto later this week.

A team of two dozen scientists and engineers assembled the sweeping panorama from 225 separate images.

"The whole panorama is there before us. It's a great opening for the next stage in our mission, which is getting off the lander and out into this field," said Michael Malin of Malin Space Science Systems, a member of the mission science team.

NASA planned to cut a final cable to free the rover from its lander more than a week after touchdown.

The umbilical cord that supplies power and communications to the rover was to be severed via programmed instructions sent late Monday or early today, officials said.

But the actual process of having Spirit roll down a ramp onto the dusty, rock-littered terrain of Gusev Crater was pushed back a day and was expected to begin late Wednesday or before dawn Thursday.

Cautious NASA scientists adjusted the rover's schedule based on analysis of photos and data it sent back, and said the rollout could be delayed another day if necessary.

That's not unusual given the complex nature of the three-month mission that began with Spirit's landing on Jan. 3.

Otherwise, Spirit was ready to go. The golf-cart-sized, unmanned rover was unfolded Friday from a tight crouch and raised to its full height of 4 feet, 11 inches. Cables holding the middle set of its six wheels were cut Saturday, leaving just the umbilical attached. And in another milestone, the robotic arm was swung up to lock in front of the rover for driving position.

'Pretty darn perfect'

The arm will scrape into rocks to help determine whether water once flowed on Mars, making it conducive to life.

The rover's status was "pretty darn perfect," with plenty of power to perform its chores, excellent communication through its high-gain antenna and a nice, flat position for its exit, said Arthur Amador, a mission manager.

On Sunday, scientists used a rover mock-up to plan a dress rehearsal of the slow dance that will put the craft into position to leave the lander. Over two days, the craft will make about a 120-degree turn to the right in three stages, each punctuated by hours as it beams back photos so engineers can check its position.

Then it will roll northwest down a ramp -- the second choice of an exit, since the forward ramp that scientists wanted to use was blocked by a bit of the lander's cushioning air bags.

Spirit will park for a day or two to give scientists a chance to study the chemistry and mineralogy of the area before it roams any farther.

One of the first things Spirit will do is extend its robotic arm to touch the soil. It also will make measurements of any rock that happens to be in range.

A spectrometer that sees infrared radiation -- heat -- will take a look at three places, including intriguing feature dubbed Sleepy Hollow that lies about 40 feet away. Scientists believe the 30-foot-diameter depression is a dust-filled impact crater, one of dozens that pock an otherwise flat landscape.

The instrument, known as a miniature thermal emission spectrometer, can help determine the makeup of rocks and soil. Last week it found traces of carbonate minerals in the area, which could support theories that the area once was a lake.

However, scientists caution that the carbonate dust also could have formed through interactions with the tiny amounts of water vapor found in the Martian atmosphere.

Future destinations include an impact crater just a few hundred yards away. The rover is capable of roaming dozens of yards a day.

The rover should spend 90 days traveling several hundred yards to analyze rocks and soil for indirect evidence of life. The duration of the mission depends on the amount of power available to the rover, which is solar-powered.

The $820 million Mars Exploration Rover project includes a second, identical rover named Opportunity that is expected to land on the opposite side of the Red Planet on Jan. 24.

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