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Wednesday, August 10, 2005

NASA Must Tackle Foam, Fuel Tank and Future of the Program - New York Times

NASA Must Tackle Foam, Fuel Tank and Future of the Program - New York TimesAugust 10, 2005
NASA Must Tackle Foam, Fuel Tank and Future of the Program
By JOHN SCHWARTZ and WILLIAM J. BROAD

EDWARDS AIR FORCE BASE, Calif., Aug. 9 - The shuttle Discovery glided back to Earth in a predawn landing here in the Mojave Desert on Tuesday, after a mission of 14 days and 5.8 million miles that successfully returned NASA to human spaceflight but also added pressure on the agency to move beyond the shuttle program.

"We're happy to be back," the shuttle's commander, Col. Eileen M. Collins, said shortly after the Discovery touched down. "We congratulate the whole team on a job well done."

The Discovery mission blended success and frustration, hope and poignancy. The shuttle program manager, William W. Parsons, called it a "wildly successful mission." But the launching was delayed repeatedly, and a problem with a fuel level sensor forced mission controllers to scrub a planned July 13 effort just two and a half hours before liftoff. And though modifications made to the external fuel tank resulted in far less launching debris than usual, five large pieces of foam - one weighing nearly a pound - popped off the tank, showing that a potentially fatal problem had not been corrected.

NASA has said that until the foam mystery is solved and the problem fixed, shuttles will not fly again.

The somewhat rocky start to the resumption of shuttle flights could end up speeding the nation's shift to the post-shuttle era, aerospace experts and analysts say. They contend that the suspension in shuttle missions could hasten the demise of the winged spaceships, already headed for retirement by 2010, and give new urgency to taking the next step in human space exploration.

"It's a good time to take a step back and think about the future of the space program," Roger A. Pielke Jr., director of the Center for Science and Technology Policy Research at the University of Colorado, said in an interview. "Choosing not to fly the shuttle would open up resources to get on sooner with what comes next."

In the weeks ahead, the National Aeronautics and Space Administration plans to unveil blueprints for a new generation of space vehicles derived from shuttle parts, though experts debate whether the agency can afford to pursue both old and new approaches simultaneously.

Louis D. Friedman, executive director of the Planetary Society, a group in Pasadena, Calif., that advocates space exploration, said that the Discovery's bittersweet flight "makes clear that the shuttle is not our vehicle of the future."

"It's barely, in the best case, our vehicle for a short time in the present," Dr. Friedman said.

One NASA adviser raised the possibility of limiting the risk to humans by removing astronauts entirely and turning the shuttles into cargo haulers to the International Space Station - an option the space agency seldom mentions in public, but has quietly studied.

Both the shuttle and the space station would require modifications to achieve automated rendezvous, as the Russians do with robot vessels that dock routinely at the station. And the agency has shunned such a step because of the public appeal of piloted space flight.

Still, some experts say the new unease over the shuttle means that such upgrades ought to be considered as a way of eliminating the risk to astronauts.

Dr. Pielke said NASA needed to work hard on alternatives even if the shuttles kept flying because they were likely to experience another catastrophic failure, from which the program could not recover.

"At any time, the shuttle may retire itself," he said, "and we ought to be planning for that."

But John M. Logsdon, director of the Space Policy Institute at George Washington University, questioned whether pouring money into some of the alternatives, especially the new vehicles derived from shuttle parts, could speed their arrival.

"If we were to retire the shuttle, it wouldn't get us new systems significantly faster," Dr. Logsdon said. "It would mean we'd end up paying Russia to haul people and cargo back and forth to the station."

He added that NASA managers during the Discovery's mission proved themselves cool even under great stress and uncertainty.

"That gives significant confidence that NASA will be able to manage the shuttle for the rest of its lifetime," Dr. Logsdon said. "The humans came out better than the machine."

On paper, the goals of this mission were straightforward: resupplying the space station and testing an external tank that had been modified so as not to shed the kind of launching debris that doomed the Columbia.

But the crew - Colonel Collins and Col. James M. Kelly, Stephen K. Robinson, Wendy B. Lawrence, Charles J. Camarda, Andrew S. W. Thomas and Soichi Noguchi of Japan - ended up having a busy two weeks.

They tested new technologies and techniques for detecting, measuring and repairing damage to insulating tiles and panels. They produced startling photography from space and conducted a bold spacewalk to pull dangling bits of cloth from the shuttle's underbelly, a procedure that the spacewalker Dr. Robinson called "the first baby step" to developing the capability for repair while in orbit. And, of course, there was the dramatic landing.

The shuttle was originally supposed to come home to the Kennedy Space Center in Florida. But unpredictable weather and rain uncomfortably close to the center led mission managers to "wave off" four Florida landing opportunities in two days, and finally to call for a change of plans.

"How do you feel about a beautiful, clear night with a breeze down the runway in the high desert of California?" asked Ken Ham, an astronaut at mission control who communicates with the shuttle.

Colonel Collins replied, "We are ready for whatever we need to do."

She fired the shuttle engines to start the re-entry, and an hour later the shuttle was streaking across the California coast from the southwest and flying north of Los Angeles on a course that took it between Oxnard and Ventura. A characteristic double sonic boom could be felt over Edwards as the craft passed overhead.

Colonel Collins took over the controls from the guidance computers once the shuttle dropped below supersonic speed, and she brought the spacecraft - at that point, essentially a brick with wings - in for its touchdown on the air base's 15,000-foot concrete runway 2-2 at 8:11:22 a.m. Eastern time, a half-minute ahead of schedule.

As the shuttle came to a stop, Mr. Ham said, "Congratulations on a truly spectacular test flight," and added, "Welcome home, friends."

At a news conference after the landing, Michael D. Griffin, NASA's administrator, said that the new external tank had provided valuable data for engineers, who could now address the foam problem.

"It's not quite a perfect tank," Dr. Griffin said, "but now they have some data."

He emphasized that space travel, even after more than 40 years, was young and still poorly understood. "It's just barely possible to do it," he said of space flight. "If anything goes wrong, it's not possible to do it."

But it is well worth doing, Dr. Griffin said. "This is an important enterprise for America and the world, for humanity to engage in," he said.

Not right away, however. Though the shuttles are grounded, Dr. Griffin said he was still hoping for a "eureka moment" that would lead to a quick fix. Whatever the chances of that happening, the landing at Edwards means that the shuttle will have to be ferried back to Florida atop one of NASA's two specially adapted Boeing 747's, a process that will cost the space agency at least a week of preparation for future flight.

The Mojave layover will prevent the Discovery from being prepared in time to serve as a possible rescue rocket for the planned launching of the shuttle Atlantis at the end of next month, if the launching goes forward on schedule. At the morning briefing, Dr. Griffin said, "We're going to try as hard as we can to get back to space this year," but he also said the flights would not be rushed.

"We will fly each shuttle mission when it is ready," he said.

Mark L. Polansky, an astronaut who has been assigned to command the Discovery on a mission next year, said the latest mission made him "very happy," but he added: "We know we have a lot of things we need to look at. We know we have work in front of us that we must do."

For the crew of the Discovery, the seven members of the Columbia crew and their fate were never far from mind.

Colonel Kelley, the pilot, acknowledged feeling "a moment of trepidation" when Colonel Collins started the engines to take the craft out of orbit and into the punishing heat of re-entering the atmosphere at 25 times the speed of sound.

During the descent, he said, he watched some of the onboard displays more than others to see whether the Discovery was showing any of the warning signs that the Columbia did two and a half years ago before it broke up and killed its seven-member crew.

Was the nose of the craft yawing to one side? Were the steering jets using more propellant than they should, as if fighting an inexorable force?

"I was watching through the period when Columbia broke apart," Colonel Kelley said. "I was looking at the things that happened to them."

To many at NASA, the most important thing is that the process has begun. It is the best way, they say, to honor their former colleagues and friends.

LeRoy Cain, entry flight director for Tuesday's landing and the final Columbia mission, said at a news briefing, "My thoughts over the past several years have drifted to Columbia thousands of times, literally." Mr. Cain suggested that the Discovery's mission might help heal the wounds created by the Columbia disaster.

"It's a great tribute to the Columbia crew that we're flying again," he said. "I know that they would want us to be flying again"

Mr. Cain, who was also entry flight director on the final Columbia mission, added, "I'm at peace with the fact that we are where I think they would want us to be."

John Schwartz reported from Edwards Air Force Base for this article, and William J. Broad from New York. Warren E. Leary contributed reporting from Cape Canaveral, Fla., and Simon Romero from Houston.

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