NASA TV via AP

In this image from NASA television, Discovery Commander Eileen Collins, center, thanks everyone for a safe flight with the space shuttle Discovery in the background at Edwards Air Force Base in California this morning. The crew from left to right are astronaut Charles Camarda, astronaut Wendy Lawrence, astronaut Steve Robinson, Collins, astronaut Andy Thomas, Japanese astronaut Soichi Noguchi, and pilot James Kelly. More Coverage Discovery's astronauts braved unknown Discovery photo gallery from Associated Press View the AP video report NASA's Return to Flight homepage

CAPE CANAVERAL, Fla. - NASA officials today hailed space shuttle Discovery and its crew for completing "a wildly successful mission" that returned America to space and safely back to Earth.

"It's going to be really hard to top this mission," NASA Administrator Michael Griffin told reporters at Kennedy Space Center after the shuttle's smooth landing at 8:12 a.m. EDT at Edwards Air Force Base in California.

Discovery had been scheduled to land in Florida yesterday morning but the return was postponed 24 hours because of low-lying clouds and rain around the cape. The same weather conditions -- this time with some flashes of lightning -- existed this morning and at 5 a.m. EDT officials in Houston made the decision to land at the backup facility in California.

It was a costly call - estimates for transporting the shuttle back across the country put the price at around $1 million - but it was the safe one.

The result was a triumphant return to Earth, with Discovery completing a 14-day mission that had been the most-scrutinized in the history of America's space program.

"Nosegear touchdown ... and Discovery is home," NASA communications officer Jim Hartsfield said, his voice betraying a sense of relief.

"Congratulations on a truly spectacular test flight," NASA's astronaut liaison Ken Ham told the crew from his post at Mission Control in Houston.

"We're happy to be back and we congratulate the whole team on a job well done," said mission commander Eileen Collins, who guided the supersonic craft to its stop on the runway in the California desert.

Collins and her six crewmates emerged from the shuttle a couple hours later and greeted NASA personnel on the landing strip.

"The crew was really anxious to get out and see the ship, which as you can see is in fantastic condition," Collins said. "We have had a fantastic mission."

Officials at Kennedy Space Center couldn't have agreed more.

"There isn't any of this that is easy," said Bill Readdy, deputy administrator for human space flight. "Eileen made it look like a cakewalk, she did such a spectacular job. And her crew as well. The entire mission has gone extremely well, beyond anybody's expectations ahead of time."

The mission's biggest success, other than the safe return of its crew, is the amount of new data - "several missions' worth" - that will be available to engineers eager to make space travel safer in the future. But while that material is reviewed, America's manned space program is on hold until NASA experts solve the problem of insulating foam breaking off during launch.

Griffin made the point that space travel is still in its infancy.

NASA TV via AP The space shuttle Discovery touches down safely on Runway 22 at Edwards Air Force Base in Calif. in this infrared television view.

"We're in, still, the very first stages of learning how to do space flight," he said. "It's just barely possible to do it. If anything goes wrong, it's not possible to do it."

Griffin and others at NASA said the Columbia and its crew, lost during a disastrous re-entry Feb. 1, 2003, were on their minds this morning as they watched Discovery approach the landing strip.

Discovery's return to flight - and the astronauts' safe return - marked a proud moment for a beleaguered space program that had spent 2 and a half years asking hard questions, then developing safer equipment and to hopefully answer them.

The lost Columbia was on the minds of the Discovery crew, as well. At the news conference after landing, Discovery co-pilot James Kelly recalled that nervous moment right before Commander Collins pushed the button for the shuttle's fiery descent home. He said he was "honestly hoping that we'd make it farther than they did. And I wished that they had made it all the way home."

"I did think about the Columbia mission coming home, but I wouldn't say it was a distraction but I would say it was more of a `We're going to get through this and we're going to press on,'" Collins said.

Collins said the United States should continue launching shuttles until the scheduled completion of the international space station in 2010.

"Some people say we should stop flying the shuttle because we had an accident -- frankly we've had two accidents -- but we are people who believe in this mission and we are going to continue it," Collins said. She was referring to Columbia and the 1986 loss of the Challenger crew when that shuttle craft exploded shortly after liftoff.

After a mission that featured the first-ever in-space repairs by a space-walking astronaut, NASA administrators were taking no chances with the Discovery landing today.

"We appreciate your understanding and good humor," Ham told the crew during their landing approach.

The astronauts began their return to Earth after being awakened last night at 8:39 p.m. EDT to the tune of The Beatles' "Good Day Sunshine."

"A day for feeling sunshine and a day for feeling the ground," said a NASA spokeswoman.

"We sure hope to get our feet on the ground today," replied mission specialist Wendy Lawrence, hoping to have spent her last night in space for a while.

The astronauts then went about preparing the craft for the return home, secure in the knowledge that this mission had been a success on just about every conceivable level.

	Terry Renna, Associated Press
	Kennedy Space Center employees clap as Space Shuttle Discovery touches down at Edwards Airforce Base in California this morning. Poor weather off the Florida coast prompted NASA to shift the landing site from the space center to Edwards.

In fact, some of the successes were inconceivable not so long ago, the best example of that being the in-space repairs. Mission specialist Stephen Robinson made an unplanned and unprecedented spacewalk to remove strips of material that were exposed between some of the shuttle's heat-resistant tiles. NASA officials were concerned that the material might cause damage during this morning's re-entry.

The hottest moments of the return to Earth usually occur about 20 minutes before landing, when the craft is burning a path through the atmosphere 43 miles up. Temperatures on the front edges of the shuttle can exceed 3,000 degrees.

Because the shuttle landed on the west coast, NASA will have to mount the craft atop a jumbo 747 jet, piggyback style, and fly it back to its home at the Kennedy Space Center for refurbishing. The cumbersome transcontinental operation will take between seven and 10 days, but there was unanimous agreement that the California landing was the thing to do.

NASA has landed 61 of its 114 shuttle missions since 1981 at KSC. One mission, in 1982, landed at White Sands, N.M., and the other 50 landings have been at Edwards Air Force Base in California.