PASADENA, Calif. — With new, tantalizing evidence of possible running water on Mars in the recent past, NASA has decided to send at least one and perhaps two large robotic roving vehicles to scout the planet's surface for signs of water, past or present.
Officials of the National Aeronautics and Space Administration announced Thursday that a spacecraft carrying the rover would be launched in 2003 on a seven-month journey to the planet, arriving in January 2004. The rover would be a larger, more elaborate version of the Mars Pathfinder rover, Sojourner, that operated for a few weeks there in 1997.
Edward Weiler, NASA's associate administrator for space science, decided to develop a landing craft with a rover for the 2003 Mars mission instead of flying another spacecraft to orbit Mars and observe it. Another orbiter is already being built and is to be launched in April.
In announcing the decision, Weiler said he was still weighing the possibility of launching a second 2003 rover at the same time. The vehicles would be sent to widely separated and diverse landing sites, probably a dry lake bed or apparent flood channel. Landing sites are to be selected on the basis of mapping data being gathered by the Mars Global Surveyor spacecraft, which has been orbiting the planet since 1997.
"We want to look into what could be an amazing opportunity, as well as a challenge, by sending two such rovers to two very different locations," he said, promising to reach that decision in the next few weeks.
The new plans for Mars exploration represent NASA's latest effort to recover from two devastating failures of Mars missions last year and to take advantage of excitement over new findings by the Mars Global Surveyor, which suggest the presence of reservoirs of liquid water hidden under parts of the dry, cold Martian surface.