Spacecraft enters orbit around Mars

PASADENA, Calif. -- The Martian sky just got a little more crowded.

After a seven-month cruise, NASA's Mars Reconnaissance Orbiter on Friday joined a small fleet of spacecraft flying around Mars, a planet known for missing-in-action space probes.

The specters of previous failed Mars missions hung in mission control at the Jet Propulsion Laboratory in Pasadena as engineers held their breath during a risky maneuver to place the probe in orbit.

After a 310 million-mile journey, the two-ton spacecraft fired its engines on cue, losing touch with controllers for a half hour as it became eclipsed by the planet.

When the orbiter emerged from the blackout, signaling to controllers that it had successfully slipped into orbit, engineers pumped their fists and gave each other bear hugs.

"Oh I am very relieved," said Jim Graf, project manager of the $720 million mission. "It was picture perfect."

The Reconnaissance Orbiter is loaded with the most sophisticated cameras and other instruments to study the planet in unprecedented detail. It's expected to beam back more data than all past Mars missions combined.

It will spend two years mapping the surface, searching for signs of ancient water and scouting for potential landing sites for future exploration. After that, the orbiter will serve as a communication relay.

The spacecraft joins NASA's orbiting Mars Global Surveyor, Mars Odyssey and the European Space Agency's Mars Express. On the surface, the surprisingly long-lived NASA rovers Spirit and Opportunity continue their robotic geology missions.

The orbiter has a telescopic camera to photograph the surface in high resolution and radar to probe underground for ice and possible evidence of liquid water. It also will help determine if human outposts can survive on the dusty planet.

Present-day Mars is dry and cold with large caps of frozen water at its poles, but scientists believe the planet once was warmer and wetter eons ago -- conditions that might have been suitable for life.

The mission's success was a huge relief for NASA, which has a mixed record of putting spacecraft into orbit around Mars. NASA lost two orbiters back-to-back -- the Mars Observer in 1993 and the Mars Climate Orbiter in 1999 -- during the orbit insertion phase.

But the Reconnaissance Orbiter performed the move without a problem.

As it neared Mars, it fired its main propulsion engines for 27 minutes, slowing down to allow the planet's gravity to pull it into an elliptical orbit that eventually will swing it as close as 250 miles above the surface.

The spacecraft will spend seven months dipping into the upper atmosphere to shrink the orbit. It is expected to beam back data beginning in November.

McCleese, who took part in the two previous failed orbiter missions to Mars, said he had been worried about the fate of the Reconnaissance Orbiter, but was elated that it was a success.

"I'm not the jinx anymore," he joked.