NASA rover lands on Mars

Robot spacecraft sends signals back to Earth

? A NASA rover plunged through the atmosphere of Mars and bounced down upon its rocky surface Saturday night, beginning a mission to roam the Red Planet in search of evidence that it was once suitable for life.

Radio signals received on Earth minutes after the landing suggested the Spirit rover survived, prompting mission controllers at NASA’s Jet Propulsion Laboratory to let out whoops of delight.

The Spirit rover is the first of two identical U.S. robots that will roam the planet’s rocky surface if all goes as planned.

The gravity of Mars had begun to tug on the spacecraft earlier Saturday from a distance of 59,000 miles, project manager Pete Theisinger said.

Spirit had appeared on track to make a “bull’s-eye” landing within a cigar-shaped ellipse inside Gusev Crater, a Connecticut-sized indentation just south of the Martian equator, navigation team chief Louis D’Amario said.

“This is essentially perfect navigation. We couldn’t have possibly hoped to do better than this,” D’Amario said.

Previously, about two of every three attempts to land spacecraft on Mars have failed.

The latest apparent failure was the British Beagle 2 lander, which has not been heard from since it was to have set down Dec. 25 on Mars.

“It’s an incredibly difficult place to land. Some have called it the ‘death planet’ for good reason,” said Ed Weiler, NASA’s associate administrator for space science.

NASA Administrator Sean O'Keefe, left, and main mission scientist Steve Squyres, center, celebrate at NASA's Jet Propulsion Laboratory in Pasadena, Calif., as they get a signal from the Mars rover Spirit after its successful landing. The NASA rover landed Saturday night, beginning a mission to roam the Red Planet.

NASA’s last attempt at landing on Mars, in 1999, failed when a software glitch sent the Polar Lander crashing to the ground. Since then, the space agency has increased oversight of its missions.

“We have done everything we know to do to ensure these missions will be a success,” said Charles Elachi, director of the National Aeronautics and Space Administration’s Jet Propulsion Laboratory.

The $820 million NASA project also includes a twin rover, Opportunity, which is set to arrive Jan. 24 on Mars.

The camera- and instrument-laden rovers were designed to spend 90 days analyzing Martian rocks and soil for clues that could reveal whether the Red Planet was ever a warmer, wetter place capable of sustaining life.

Today, Mars is a dry and cold world. But ancient river channels and other water-carved features spied from orbit suggest Mars may have had a more hospitable past.

“We see these intriguing hints Mars may have been a different place long ago,” said Steve Squyres, the mission’s main scientist.

The rovers were built to look for evidence that liquid water — a necessary ingredient for life — once persisted on the surface of the planet. A direct search for life on Mars is at least a decade away, NASA scientists said.