Just after 2 a.m. EST today, Spirit's computer powered the rover down to conserve energy during the cold martian night. It briefly woke up twice this morning to beam stored data to the Mars Global Surveyor and the Mars Odyssey orbiters for relay back to Earth. The rover is expected to wake up for its first full day on Mars just after 6 p.m. EST.

Spirit sitting on its lander following touchdown last night. Credit: NASA/JPL

The primary goal of today's activity is to deploy, check out and begin using the rover's main high-gain antenna, the link flight controllers will use throughout the mission to send commands to the spacecraft. Overnight, scientists hope to downlink a spectacular color image from Spirit's high-resolution stereo panoramic camera, a mosaic called the Sol-2 (Mars day 2) postcard made up of seven frames looking directly ahead of the rover. The mosaic is expected to be released during a news conference at noon Tuesday.

The black-and-white images received early this morning were taken by low-resolution navigation cameras, or Navcams. The panoramic camera, called the Pancam, will take images that are 14 times sharper. The Sol-2 postcard "will be a truly spectacular image once we get that one down to the ground," said Steve Squyres, the Spirit principal investigator. "That will be taken this afternoon Mars time and will come down on one of the subsequent UHF (satellite) passes."

Spirit ended up with just a 2-degree tilt. All systems are operating normally, although the martian atmosphere is slightly more opaque than expected, presumably because of a dust storm on the other side of the planet. That opacity is reducing the amount of sunlight reaching Spirit's solar arrays, which are generating only about 83 percent of their predicted power. Mission manager Jennifer Trosper said the slightly reduced power will not have any significant impact on Spirit's mission.

As it turned out, Spirit ended up facing nearly due south, putting the rising Earth, at times, directly behind the Pancam mast as viewed from the high-gain antenna. To eliminate any possible signal degradation, engineers developed procedures to swing the antenna 180 degrees to provide a direct line of sight. The first high-gain communications session is expected later today.

Engineers are still assessing the best route for Spirit to roll off its lander. Earlier today, they were concerned a large rock might be blocking the right side of the rover's forward egress route. But additional analysis shows what was thought to be a rock more likely is part of a deflated airbag that is bunched up under the base of the lander. A similar bubble of airbag material is also present on the left side of the forward egress route. Engineers may be able to command additional airbag retraction to eliminate the obstacles. But other routes are available as well and Trosper said engineers are not worried about finding a safe way off the lander.

It will take eight days or more to prepare Spirit for its eventual roll off. The rover currently is hunkered down on its landing petal with two of its six wheels folded up and out of the way. On Monday, engineers plan to begin the two-day process of "standing up" the rover so the two forward wheels can be unfolded. Various clamps and restraints used to secure Spirit and its appendages for launch and landing will be released over the next several days as the ramp up to roll off proceeds.

"What we've been focusing on on the science team is what we're going to do after we drive off the lander," Squyres said. "Now, we've got a long way to go before we're ready to do that, we're looking at eight or nine (days) of very important engineering activities to very cautiously, very safely get this vehicle ready to begin its exploration.

"Once we've done that, the science team is starting to think about what will come next," he said. "We will, by the time we egress, by the time we've got six wheels in the dirt, we'll have a complete color stereo Pancam panorama, we will have a complete (infrared) panorama. That will provide the framework, if you will, for where our explorations will take us in the days immediately following our egress."

The first priority, once Spirit has rolled a few feet away from the lander, will be to test the craft's robot arm on nearby rocks and soil. Only then will Spirit be commanded to set off on its own.

No targets have been selected yet. But Squyres said initial navigation camera images show intriguing depressions nearby with clearly defined rims, or lips, similar to road cuts on Earth. The lip of one such depression "exposes some rock in a very interesting and tantalizing way," Squyres said.

"I cannot wait to see the first Pancam images of this," he told reporters. "Again I remind you that these are Navcam images, which are low-resolution cameras and then we've scrunched them down by a factor of four in both directions. Pancam is three-and-a-half times better than Navcam. So if you do the math, we're going to have pictures that are 14 times sharper than this coming very soon. And I'm very, very eager to see what that looks like.

"So these depressions, they have these sort of steep lips around the outside and exposed on that lip is some rock. It may be a very tantalizing place to go. One thing I want to express a little caution about, though, is that we don't know that that depression, which is filled with very smooth-looking soil, I don't know for sure it's not a rover trap. And we're going to have to be a little bit cautious, we want to get a good close look at that, make sure it's nicely compacted stuff that we wouldn't sink too deeply into it when we traipse across it. This is someplace we haven't been before and we're going to tread carefully."

Squyres closed his opening remarks by passing on good wishes to Britain's Beagle 2 lander team. Beagle 2 entered the martian atmosphere Christmas Eve, U.S. time, and hasn't been heard from since. The Mars Express orbiter that carried the British lander to the red planet is now in its final orbit and over the next few days, the European Space Agency orbiter will continue the search for Beagle 2.

"I got a very nice phone call ... last night from Colin Pillinger," Squyres said. "Colin Pillinger is the principal investigator on the Beagle 2 lander. And he called me late last night, a very, very gracious phone call, very kind, in which he congratulated us and I very much wished him luck. I haven't given up on Beagle 2 yet and I know Colin hasn't, either. Beagle 2 has the potential to do some fantastic science at Mars. They still have some communication capability to check out with the Mars Express orbiter. ... I just want Colin and everybody in the UK to know there's a whole bunch of people on this side of the Atlantic who are rooting for them."

Video coverage for subscribers only:
   VIDEO: MIDDAY BRIEFING ON SPIRIT'S HEALTH AND LANDING SITE QT
   VIDEO: TAKE SIMULATED FLIGHT OVER THE GUSEV CRATER! QT
   VIDEO: BEHIND THE SCENES AT MOMENT OF TOUCHDOWN QT
   VIDEO: CHEERS AND SCREAMS WHEN SPIRIT CONFIRMED ALIVE QT
   MORE: COMPLETE MARS EXPLORATION ROVER VIDEO REPORT
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