The most exhaustive test flight in the space shuttle fleet's 24-year history ended Tuesday with the shuttle Discovery's pre-dawn touchdown in California. Now that the crew is back safely, the shuttle faces an uncertain future.
After 14 days, 219 Earth orbits and 5.8 million miles in space, Discovery landed safely at 8:11:22 a.m. ET at Edwards Air Force Base. "Discovery is home," the NASA TV commentator announced.
"Congratulations on a truly spectacular test flight," astronaut Ken Ham at Mission Control radioed to the crew as the shuttle stopped on the runway. “Welcome home, friends.
"We're happy to be back," replied commander Eileen Collins, who piloted the 100-ton spacecraft to its landing. "We congratulate the whole team on a job well done."
The mission exposed how vulnerable the shuttle fleet remains, despite a tremendous amount of money and effort invested in the first U.S. manned space mission in the 2 1/2 years since the Columbia tragedy.
Shortly after liftoff July 26, a 1-pound chunk of foam insulation fell from the fuel tank — the very thing that doomed Columbia — but it missed Discovery. Still, NASA grounded all shuttle flights until engineers fix the problem.
“We’re going to try as hard as we can to get back in space this year,” NASA Administrator Michael Griffin said at a post-landing news conference. “But we’re not going to go until we’re ready to go.”
Shuttle managers freely acknowledged the foam mistake, while stressing that the inspection, photography and other shuttle data-gathering systems put in place for this flight worked well. What’s more, NASA officials said no severe damage was detected on Discovery while it was in orbit.
“I hope this shows people that we’re coming back,” NASA spaceflight chief Bill Readdy said from Cape Canaveral, Fla. “We’ve got some more work to do. We know what we need to do and we’ll do it.”
‘We had a fantastic mission’
Commander Collins and the other members of Discovery's crew — Jim Kelly, Steve Robinson, Soichi Noguchi, Andy Thomas, Wendy Lawrence and Charlie Camarda — took a post-landing inspection tour around Discovery as it sat on the runway at Edwards.
"We have had a fantastic mission," Collins said, standing on the tarmac in front of the shuttle. "We are so glad to be able to come back and say it was successful." She noted that the crew had been anxious to inspect Discovery for damage and was pleased that it was in such good shape.
"It's absolutely fantastic to be back here to the planet Earth," Collins said at a news conference a few hours later. "We had a great mission. We got a few more days than we expected and we used them wisely," she said.
The crew's families, along with top NASA officials, had been awaiting the shuttle's return to the Kennedy Space Center in Florida, where Discovery had launched on July 26. Rain and thunderstorms in Florida forced the shuttle to land in California instead, however.
The Columbia disaster weighed heavily on everyone’s minds as the shuttle made its descent to Earth. Co-pilot James Kelly 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.”
Unlike previous Edwards landings, in which throngs of spectators gathered for a shuttle return, the public was barred from viewing Discovery due to increased security after the Sept. 11 terrorist attacks.
“I was pretty anxious all day,” flight director LeRoy Cain said at a post-landing news conference at Johnson Space Center in Houston. He said there were a couple of anomalies during re-entry but labeled them “insignificant.”
“Today we honored the Columbia crew. We brought Discovery home safely,” shuttle program manager Bill Parsons said. “It’s a great day.”
President Bush also weighed in with congratulations. "It was an important step for NASA as it regains the confidence of the American people and begins the transition to the new mission we’ve set out for NASA," he said. "So congratulations, Commander Collins. It’s quite an achievement."
The first post-Columbia mission accomplished its two goals: to resupply the space station, and to test the inspection and repair techniques that NASA developed in the wake of Columbia's catastrophic breakup in 2003.
Collins highlighted these achievements at the post-landing news conference at Edwards and spoke at length about the importance of human space exploration. The mission was both "an absolutely breathtaking challenge" and a "huge achievement," she said. Space exploration, she said, "is making life on Earth better for all of us."
The biggest accomplishment, she said, was just "getting the shuttle flying again."
"The Columbia crew believed in what they did, they believed in the space mission," and so do we, Collins said. "I ask you to keep supporting us. ... Space exploration is a fantastic part of the human experience."
The new inspection techniques did show two significant problems: the chunk of foam insulation that broke off from the external fuel tank after launch and two protruding bits of filler material that had to be plucked off Discovery's belly during a spacewalk by Robinson.
This unprecedented repair job in space may be laying the groundwork for long-duration missions such as those talked about to the moon and Mars, Robinson said Tuesday. "Things are going to fail," he said, and this kind of up-close work with the shuttle skin showed what could be done when they do.
Robinson also paid tribute to Lawrence, who operated the robotic arm that maneuvered him so close to the shuttle's exterior. She "has no windows," he pointed out. "It's like flying a jet by watching TV." He said he felt very comfortable in position, like he could have done several different repairs there had he needed to.
Discovery's flyaway foam was detected thanks to unprecedented in-flight imagery of the shuttle's ascent, and the dangling gap fillers were noted during the most detailed on-orbit inspections ever conducted. The inspections turned up still more flaws, including minor damage to shuttle tiles and a torn thermal blanket — but NASA decided those posed no risk to Discovery's safe return.
Collins said she took a quick look at the thermal blanket after landing, and it did not look like there was a significant change on re-entry. She wasn't concerned about the blanket, she said, and praised NASA for making a good decision.
Such problems might have gone unnoticed on past flights, because the inspection procedures were not nearly as rigorous. NASA officials said the problems were all part of the challenge of operating an experimental space vehicle — which is how they have come to see the shuttles since the Columbia disaster.
Investigators said Columbia and its crew were lost because a piece of flying foam — bigger than the one that was seen coming off Discovery's tank — struck the orbiter's left wing, opening up a gap that let hot gases in during Columbia's atmospheric re-entry 16 days later. They also faulted NASA's "broken safety culture" for not paying close enough attention to things that might go wrong.
'We felt very safe'
As part of a $1.5 billion effort to remedy those faults, NASA added scores of cameras to record Discovery's launch, built a new kind of laser- and camera-equipped inspection boom to survey the shuttle's protective skin while on orbit — and encouraged more open discussion of potential problems. Discovery's astronauts tested patches and fillers that could be used to mend gaps in the shuttle's tiles or reinforced panels, and NASA said those repair tools would be improved for future flights.
Collins praised the shuttle and the people who built it. "The space shuttle orbiter performed magnificently," she said, every system "worked perfectly." There were a "few microswitch problems here and there," she said, but the "folks that built this orbiter and maintained it did a fantastic job and we felt very safe."
Discovery's crew also had to cope with a series of delays, from launch to landing. A fuel gauge glitch caused the launch to be postponed 13 days until July 26. While in flight, the mission was extended a day to give the crew more time to transfer supplies to the space station. And the landing, originally set for Monday, was delayed a day by poor weather in Florida. The poor weather persisted Tuesday, forcing NASA to divert Discovery to California.
Discovery was the first shuttle to visit the space station since 2002 and a large part of the mission was spent transferring supplies and taking away tons of trash and old equipment from the station. Collins praised Camarda and Lawrence for their efforts in the transfer. Lawrence, the chief of transfer, "called us her drones," Collins recalled. "She kept us working, taking bags of supplies back and forth."
In addition to testing the repair tools and making the gap filler fix, spacewalkers Robinson and Noguchi repaired one of the station's gyroscopes and replaced another one, bringing the station's four-gyro guidance system to full strength for the first time in three years. Noguchi, along with Camarda, was a space rookie, "but you would never have known it," Collins said.
Japanese astronaut Noguchi said it had been an honor to "join this great American crew." One of his favorite memories, he said, was sharing some great Japanese food with the shuttle and station crews during a joint meal.
"I feel like going back to the station tomorrow," he said. "I really enjoyed every moment of the flight."
Collins and others shared similar sentiments, saying what they'd miss the most was the view of Earth from space. While they saw "some of the most beautiful parts of the Earth," the astronauts also saw evidence of deforestation and erosion taking place, Collins said. The view at night was also stunning, she said, adding that they flew through the southern lights at one point.
'The torch is now passed'
Even before Discovery was launched, an oversight panel said the space agency had to do more to address potential debris problems. At a minimum, the problems with foam-shedding and the tile gap fillers will have to be addressed before NASA launches Atlantis, the next shuttle in line.
Readdy compared the return to flight to a relay race. "The torch is now passed to Atlantis and the STS-121 crew," he said.
Teams are already at work looking at how to fix the remaining problems, said Readdy, who, like others at NASA, stressed the difficulties of spaceflight. "Eileen made it look like a cakewalk ... but there wasn't a single part of this mission that was easy."
Currently, Atlantis is due to fly another test mission to the space station no earlier than Sept. 22, but even during Discovery's flight, deputy shuttle manager Wayne Hale said he didn't consider that "a serious launch date." If Atlantis doesn't lift off by Sept. 24, the next opportunity would be in early November.
Tuesday's landing was the 50th shuttle landing at Edwards since 1981, but Discovery took a different flight path than its predecessors. The shuttle skirted Los Angeles because of new public safety considerations in the wake of the Columbia disaster, which rained debris onto Texas and Louisiana.
NASA said it would take about a week before they could begin ferrying Discovery back home to Cape Canaveral, and noted that because of the weather, doing so would take two days. The shuttle will be flown atop a specially modified 747, with a pathfinder aircraft flying in front to look for the safest flight path.
MSNBC's Alan Boyle and The Associated Press contributed to this report.