By Guy Gugliotta
Washington Post Staff Writer
Wednesday, July 5, 2006; A01
CAPE CANAVERAL, July 4 -- Space shuttle Discovery, trailing a tail of yellow fire and billowing gray smoke, launched into central Florida's dazzling summer sky Tuesday like an outsize Independence Day Roman candle.
After two weather delays over the weekend and questions about lost insulation foam from the orbiter's external fuel tank, Discovery enjoyed an incident-free countdown on its way to the first launch of a space shuttle on the Fourth of July.
Shuttle project manager N. Wayne Hale Jr. said the external tank "performed very well indeed." He said there were five instances of foam loss during launch, but "we saw nothing that gives us any concern about the health of the vehicle."
A report by astronaut Michael E. Fossum that heat shielding fabric had come loose from the orbiter was, Hale said, ice that drifted away from the nozzles of the shuttle's main engines, which are cooled with liquid hydrogen during launch.
"We have seen it come off several times," Hale said at a news conference. "You look at it, and you say, 'It's got to be fabric,' but it's clearly ice."
He said NASA engineers would continue analyzing launch photography and imagery over the next few days. In addition, a painstaking on-board inspection of the orbiter will consume most of the crew's first day in space Wednesday.
Hale told reporters that all the incidents of foam loss from the tank occurred at least 2 minutes 53 seconds after launch, well after what engineers regard as the danger period for damage to the orbiter. Impacts that occur less than a minute after launch do no harm because the shuttle has not built up enough speed, while impacts after 2 minutes 15 seconds have no effect because the atmosphere is so thin.
Videotape of the external tank showed that most of the debris incidents involved pieces of foam falling away in an almost spray-like pattern, and Hale said all but perhaps one fragment were smaller than the smallest piece that engineers believe could endanger the orbiter.
Launch day opened with a rain shower, but dawn brought beautiful sunshine and the welcome news that the chances of an on-time launch had increased overnight from 60 to 80 percent. Weather conditions changed from "red" early in the day to "green" for "go" by midmorning, and stayed that way through launch.
Mission Commander Steven W. Lindsey and the six other members of Discovery's crew, wearing their bright orange launch suits, left the crew's quarters shortly before 11 a.m. All except European Space Agency astronaut Thomas Reiter, a German national, waved U.S. flags. Reiter had a German flag.
A bit more than an hour later, crewmembers were strapped into their seats to await liftoff from the Kennedy Space Center's launchpad 39B. At 2:25 p.m., launch director Mike Leinbach polled his team on Discovery's readiness and heard nothing but "go." "The weather is beautiful," Leinbach radioed the crew. "America is ready to return the shuttle to flight. Good luck and Godspeed, Discovery."
"I can't think of a better place to be on the Fourth of July," Lindsey said.
About 13 minutes later, at 2:37 p.m. and 55 seconds, Discovery lifted off, rattling windows five miles away.
Liftoff followed a tense off-day in which engineers studied the loss Sunday of a bread-crust-size piece of foam insulation from the external tank, finally deciding the mishap posed no problems for launch.
Despite what appeared to be a minor glitch in launch preparations, any problem with the external tank foam rates major attention from NASA in the aftermath of the 2003 loss of the space shuttle Columbia. It disintegrated on reentry after a large piece of foam breached the orbiter's heat shielding during launch.
Foam loss during a launch last July grounded the shuttle fleet for a year, and Tuesday's launch was preceded by prolonged disagreement among top NASA officials over whether engineers should have first redesigned foam insulation covering brackets that hold pressure lines and cables to the side of the orbiter's external fuel tank.
Hale said late Tuesday that the decision to eliminate a foam ridge from the external tank after last year's flight "appeared to be a good aerodynamic move" but said it was impossible as yet to assess the effect of this modification on the bracket foam.
NASA Administrator Michael D. Griffin made the decision to fly the current mission, pointing out that the dangers of foam damage threatened the shuttle, but not its crew, which could take "safe haven" aboard the space station.
"I run the agency, and I'm responsible for the decisions I make or don't make," Griffin said in a recent interview. "If I stand down, I'm responsible for spending another $4.5 billion of taxpayers' money without flying for a year. That's what it means to be boss."
The mission is a critical benchmark for the shuttle program, for NASA and for President Bush's "Vision for Space Exploration," which calls for the shuttle to be retired in 2010 after finishing construction of the space station. After that, NASA will focus on returning to the moon by 2020 and eventually traveling to Mars.
For this ambitious program to be fulfilled, the shuttle must fly more than four times per year for the next four years. While another Columbia-style tragedy would undoubtedly shut down the shuttle program, Griffin has refused to speculate on the consequences of a relatively minor problem such as last year's, which could ground the shuttle for months.
"That question is too open-ended," Griffin said. "What this program needs is restoration of a normal ops tempo. If we have another interruption, we'll deal with that when it comes up."
In a partial signal of a "return to normalcy," Discovery will deliver Reiter to the space station, where he will join commander Pavel Vinogradov of Russia and flight engineer Jeffrey Williams of the United States, bringing the station's crew up to its normal complement of three for the first time since the Columbia tragedy. Reiter will stay aboard for about six months.
Besides Lindsey, with three previous space missions, and Reiter, with one, Discovery's crew includes space veterans Mark E. Kelly, the orbiter's pilot, and spacewalker Piers J. Sellers. Cargo handlers Stephanie D. Wilson and Lisa M. Nowak are both space rookies, as is Fossum, the second spacewalker.
Discovery's 12-day mission will focus on spacewalks to test new shuttle equipment and repair station machinery. If, as seems likely, managers add a day to the trip, Sellers and Fossum will undertake a third spacewalk to test repair techniques for the "reinforced carbon-carbon" thermal shielding on the leading edges of the orbiter's wings and on the nose cone.