Another seven days of waiting before the rover Spirit gets rolling

By David Brand

NASA/JPL/Cornell University Mars in 3D Click on the image for a high-resolution version (3322 x 2934 pixels, 1060K)

At a press briefing today (Jan. 7)at the Jet Propulsion Laboratory, which is managing the twin-rover Mars mission for NASA, engineer Art Thompson said that "at this point we don't plan on getting off before Wednesday," three days beyond the originally planned rover roll-off onto the crater floor. He said that mission planners had been "overly optimistic" and that the delay is due to "a couple of hiccups."

With four Martian days, or sols (24 hours, 39 minutes and 35 seconds in Earth terms), behind it, the rover sent back the first color stereo picture of the area around the lander taken by the mast-mounted panoramic cameras, or Pancams. The left-right images, viewed by the news media in red-green glasses, give three-dimensional images of "nifty-sized objects and interesting science targets," in the words of Cornell astronomer Jim Bell, who is leading the Pancam team.

In the image he pointed out hills about two kilometers (1.2 miles) away and 50 to 100 meters (165 feet to 330 feet) high. He described them as "obviously a driver target" for the rover. Some of the rocks around the lander, he said, "are quite sharp and angular, others are smooth. You really can get a sense of the shapes of the rocks, their size distribution, their distances." He added that "these are the kinds of measurements we will be using to determine exactly how to drive the rover through this path to whatever destination we choose."

The science team for the two rovers, Spirit and Opportunity, is being led from Cornell by astronomy professor Steven Squyres.

The image was the second of eight multiframe images that are being returned to Earth that ultimately will form a 360-degree panorama of the landing site. The steroscopic effect was similar to that presented by the first pictures from the rover Jan. 4, although those were in black and white and taken by the lander's low-resolution navigational cameras. The latest color image has 16 times the spatial resolution of the first pictures, said Bell.

The image data was relayed in two passes by the Mars Odyssey orbiting satellite because the rover's direct-to-Earth high gain antenna has been under testing by mission engineers since a spike occurred in the amount of electricity drawn by one of its motors when it was first used Jan. 4. However, mission officials said the antenna is now working well, and they plan to use it on Mars Thursday, or sol 5.

The retraction of the protruding airbag is presenting more of a problem because it is so close to the rover's front petal, which will provide the ramp for the vehicle's roll-off into the crater. The fear is that unless it is fully retracted it could strike the rover's solar panels. On sol 5, officials plan to slightly raise the lander's left petal and "lift and tuck" the airbag underneath the lander.

Although the rover can drive off the lander in any direction, the preference is for an exit from the front. "We want nothing more than to get this puppy off the lander. We are chomping at the bit," said Thompson.

When the rover does finally emerge, the science team's favorite direction is southeast, said Thompson. However, said Bell, "We're going to keep our minds open, collect some measurements and not get ahead of ourselves."

Science team officials are busily debating the likely geological origin of the rocks and soil around the lander, and suggestions have ranged from lake bed deposits covered by lava flows to rocks brought in by rivers. Bell, who is an associate professor of astronomy at Cornell, noted that there even have been suggestions of glaciation. But, he said, "you can find fault with any hypothesis." He added, "We haven't seen any unambiguous evidence for one theory over another."

Bell described the scene in the Pancam room at JPL as the color images arrive and the team gets "slow glimpses" of the world around the rover. "When the team saw the latest image arrive, there was generally a cry of 'whoa,'" he said.

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