HEADING TO MARS
Lander and rovers are expected to touch down, examine martian rocks
The search for clues to Mars's history is intensifying. A fleet of spacecraft from the U.S. and Europe is expected to arrive at the red planet over the next few weeks with instrument-laden rovers and a lander that will examine martian rocks for evidence of past water activity and even life.
And the tools they're carrying have evolved since previous Mars missions. Along with standard instruments such as spectrometers and cameras, these craft are also toting microscopes and scratching tools to expose fresh rock.
||REVEALING The rock abrasion tool on the rover's robotic arm can grind away a rock's surface, allowing scientific instruments to analyze the rock's interior.
Beagle 2, a lander aboard the European Space Agency's Mars Express spacecraft, is scheduled to touch down on the martian surface on Dec. 25 in an ancient impact crater that may have been wet. After it comes to rest, Beagle 2 will begin examining the surrounding soil with its instruments.
NASA's Mars Exploration Rover project features two rovers dubbed Spirit and Opportunity. Spirit is slated to land on Jan. 3 and Opportunity, on Jan. 25. Each rover will spend about three months roaming the surface.
Scientists with the NASA project have spent the past six months rehearsing surface operations, and "we're ready," says Steven W. Squyres, astronomy professor at Cornell University and project leader for the U.S. rovers' instrument packages. "It's been a very long wait, and we're eager to get on with it."
Unlike NASA's pint-sized rover Sojourner, part of the 1997 Mars Pathfinder mission, Spirit and Opportunity are as big as golf carts and weigh nearly 400 lb each. They can carry more instruments than Sojourner and travel longer distances, Squyres says. And given the risky nature of robotic space exploration, having two rovers increases the chances of success.
The rover landing sites are near the martian equator. One is in the middle of the Gusev crater, which might once have held a lake. The other site is on the Meridiana Planum, a plain containing gray hematite, a mineral formed under wet conditions.
Spirit and Opportunity are each carrying identical packages of instruments designed to chemically and physically characterize the rocks they sample. The instruments will look for minerals that could have been formed during precipitation or by hydrothermal activity.
Once the rovers have landed, they'll spend a week unfolding their instruments and tuning up. Then they will begin transmitting their findings to Earth. Stay tuned.