The U.S. Mars rover is poised to make its first foray onto the red planet's surface in a few hours, now that mission controllers have finished pointing it in the direction it is going to go.
During the past couple days, engineers at the Jet Propulsion Laboratory in California have rotated the Spirit rover one-third of a turn on the landing platform.
This was necessary because airbags that cushioned the landing could not be fully retracted. They continue to partially block the preferred exit route down a front ramp. So rover will take a secondary pathway off the lander, covering three meters on its first try.
In addition, mission manager Jennifer Trosper says that scientists have finished taking very sharp panoramic images of the terrain around the spacecraft. "So, really, there is nothing left to do on the lander for Spirit," said Ms. Trosper. "So tomorrow we are going to egress onto the surface of Mars."
Scientists will be seeking evidence in the Martian soil and rocks that water once flowed there and made conditions suitable for life.
The mission strategy is to investigate the terrain closest to the landing site, then slowly proceed further away. Cornell University scientist Steven Squyres says the rover will use its arm to dig material from a crater about 30 meters from the lander and drive toward a mountain range three kilometers away.
"I cannot tell you that we are going to reach those hills. I do not know how close we are going to get," admitted Mr. Squyres. "We are going to get as close to them as we can. As we progress across the landscape, we will investigate materials along the way and hopefully learn more and more about not only what lies on these plains and what lies below them but what lies above them on those hills as well."
On Thursday and Friday, Spirit will conduct coordinated research with two satellites orbiting Mars - the U.S. Odyssey spacecraft and the British Mars Express, which arrived after Christmas.
The companion lander to the Mars Express, the Beagle, has failed to communicate with Earth after its supposed touchdown on Christmas. But researchers say the satellite has a variety of European instruments that complement the Mars Rover mission.