Phoenix spacecraft lands on Mars

Cheers and applause echoed through the halls of NASA's Jet Propulsion Laboratory in La Cañada Flintridge, which is managing the mission.

"Touchdown signal detected," said Richard Kornfeld, a communications specialist. "Welcome to the northern plains of Mars."

The landing of the 7-foot-tall, 904-pound craft, built by Lockheed Martin Space Systems Co., was an elegant feat of engineering and artistry.

"We have the best team in the world," said an exultant Barry Goldstein, the project manager, who has devoted the last five years to this mission.

About two hours after the landing, the first images came back from Phoenix crystal clear, showing that its solar arrays had been successfully deployed and the craft was sitting on a stable and safe surface.

"These images are telling us we have a healthy configuration for the spacecraft," said Dan McCleese, chief scientist for JPL. "This looks like a good place to start digging.

"We haven't sunk into the surface very deep at all," he added. That could indicate that Phoenix is sitting on a Martian version of permafrost.

The black-and-white pictures gave scientists a glimpse of a landscape different from anything they have seen on Mars before. They appeared to show small rocks, soil and evidence of fissures.

Phoenix's touchdown is the first successful landing on Mars since NASA's twin rovers arrived in 2004, and the first soft landing -- using a parachute and thrusters instead of protective air bags -- since the Viking missions 32 years ago.

Given the technical difficulty of the landing, and the fact that prior to Phoenix only five of 12 spacecraft had successfully landed on Mars, scientists and engineers were more anxious than usual.

Peter Smith of the University of Arizona, the mission's lead scientist, compared the descent to the surface to a window washer falling from a high-rise.

The name Phoenix, referencing the mythical bird rising from its own ashes, was derived from the Mars Polar Lander, which was lost in 1999 as it descended toward the surface.

The entry-descent-landing period, when the lander separates from the spacecraft, enters the atmosphere and brakes from 12,000 mph to 5 mph, has been described as "seven minutes of terror."

The landing, however, appeared to be almost picture perfect. Each event, from the deployment of the parachute to the firing of the thrusters that slowed the lander for the final 300 feet to the surface, occurred just as JPL had planned.

As Phoenix whisked through the Martin atmosphere, temperatures on its heat shield reached 2,600 degrees Fahrenheit.

After slowing in the thin atmosphere, the craft's parachute opened, reducing its descent to 5 mph as it approached within 100 feet of the surface.

Fears that Phoenix might land on rocks failed to materialize. It came to a rest tilted just a quarter of one degree.

"It's almost horizontal to the surface," Smith said, smiling.