WASHINGTON, Jan. 4 (UPI) -- The first of two NASA robotic rovers launched last June on a three-month mission to search for evidence of water on Mars landed safely Saturday night after surviving a dangerous plunge through the planet's atmosphere.
The craft, called Spirit, slowed from its entry speed of about 12,000 mph by applying braking rockets and parachuting into the thin Martian air, then bouncing along the surface cushioned by airbags. After settling to a stop at approximately 11:35 p.m. EST, the craft radioed back to mission control that it had landed safely.
"This is a big night for NASA," said agency chief Sean O'Keefe. "We're back! I'm very, very proud of this team, and we're on Mars again."
Spirit landed within an ellipse about 39 miles long and 2 miles wide in a low-lying area called Gusev Crater. Three hours after landing, at about 2:30 a.m. EST, Sunday, Spirit began transmitting the first images of the surrounding terrain.
Navigation team chief Louis D'Amario called the feat "hitting the bull's-eye" and said the precision of the landing was like threading a needle from 20 miles away. "This is essentially perfect navigation," he said. The team, operating from NASA's Jet Propulsion Laboratory in Pasadena, Calif., had set the spacecraft on a perfect course over the past two days with maneuvers that had eliminated the need for last-minute corrections before its atmospheric entry.
The JPL team did order the craft to deploy its parachutes about two seconds earlier than scheduled because "a dust storm seen on the other side of the planet has caused global heating and thinning of the atmosphere at high altitudes," said Mark Adler, Spirit's mission manager.
Messages between JPL and Spirit take about 10 minutes each way, even at the speed of light, because Mars currently is about 106-million miles from Earth.
Spirit will take the next nine days to unfold its five hexagonal solar panels and complex sensor array, deploy its robot arm and six wheels, and scan its surroundings with twin, high-resolution digital cameras. Mission specialists then will order Spirit to begin moving about the landscape toward rocks of interest. The golf-cart-sized rover will grind down the surface of rocks with a grinder, then analyzing the pristine material beneath with a spectrometer and other instruments.
Eventually, scientists hope Spirit will travel up to 20 miles across Gusev, an ancient impact basin that scientists think once was the bottom of a large lake.
"We see dried up river beds on Mars. We see dried-up lake beds," said mission scientist Steve Squyres of Cornell University in Ithaca, N.Y. "We see these intriguing hints that Mars may have been a very different world in the past. Now, if you want to find out whether or not those hints are really telling us that Mars was once a place that would have been suitable for life, then what you really need to do is go there and read the story in the rocks."
The celebration over Spirit's success was the second in two days for JPL engineers and scientists. On Friday, the Stardust spacecraft successfully plowed its way through a dusty halo around comet Wild 2 and became the first craft to capture material left over from the birth of the solar system. Stardust is scheduled to return the comet dust to Earth, via a tiny landing capsule, in January 2006.
Spirit's twin lander, called Opportunity, is scheduled to land on Jan. 24 in an area called Meridiani Planum, a flat plain near the Martian equator on the opposite side of the planet from Gusev. Meridiani also is thought to be a site of an ancient lakebed and Opportunity will be looking for signs of water there.
Meanwhile, British scientists are still awaiting a signal from the Beagle 2 lander, which plunged through the Martian atmosphere on Christmas Day. So far, all attempts to detect the 70-pound lander's signal have been unsuccessful.