In a majestic U.S. Independence Day liftoff, Discovery and its crew of seven blasted into orbit Tuesday on the first space shuttle launch in a year, flying over objections from those within NASA who argued for more fuel-tank repairs.
NASA's first-ever Fourth of July manned launch came after two weather delays and a new crack in foam insulation on the fuel tank. Shuttle managers said early video images showing small pieces of debris breaking away were not troubling.
NASA Administrator Michael Griffin said of the launch: "They don't get much better than this."
It was Griffin who chose to go ahead with the launch over concerns from the space agency's safety officer and chief engineer about foam problems that have dogged the agency since Columbia was doomed by a flyaway chunk of insulation 3 1/2 years ago.
Discovery thundered away from its seaside pad at 2:38 p.m EDT (1838 GMT).
About three minutes later, three or four pieces of debris were seen flying off the tank, and another popped off a bit later, said shuttle program manager Wayne Hale. Discovery was so high by then that there wasn't enough air to accelerate the pieces into the shuttle and cause damage, he said.
"That is the very raw, preliminary data," Hale said. "It will be a while before we get a complete picture of what happened during the ascent."
Hale and others on the launch management team were in a jubilant mood over the smooth liftoff.
"No, we did not plan to launch on the Fourth of July, but it sure did work out to be great to launch on Independence Day," said Hale, who was wearing a patriotic tie.
Commander Steven Lindsey, an Air Force fighter pilot, was at Discovery's controls and aiming for a Thursday linkup with the international space station.
"Discovery's ready, the weather's beautiful, America is ready to return the space shuttle to flight. So good luck and Godspeed, Discovery," launch director Mike Leinbach said just before liftoff.
"I can't think of a better place to be here on the Fourth of July," radioed Lindsey. "For all the folks on the Florida east coast, we hope to very soon get you an up-close and personal look at the rocket's red glare."
It was unclear for a while Monday whether Discovery would fly at all.
A slice of foam, not much bigger than a crust of bread, fell off an expansion joint on the external fuel tank as the spacecraft sat on the launch pad. Shuttle managers concluded Monday night after intensive engineering analysis that the remaining foam on that part of the tank was solid.
Engineers said the piece — 3 inches long (7.6 centimeters) and just one-tenth of an ounce — was too small to pose a threat even if it had come off during launch and smacked the shuttle. Inspectors devised a long pole with a camera to inspect the joint and found no evidence of further damage. NASA also made sure there was no excessive ice buildup at that spot Tuesday.
The fallen foam, albeit harmless, added to the tension already surrounding this mission.
NASA's chief engineer and top-ranking safety official objected two weeks ago to the 12-day mission without eliminating lingering dangers from foam loss, considered probable and potentially catastrophic.
They were overruled by shuttle managers and, ultimately, Griffin. He stressed the need to get on with building the half-done, long-overdue space station before the shuttles are retired in 2010 to make way for a moonship, per President George W. Bush's orders.
Griffin said he welcomed the debate over Discovery's launch and acknowledged that the space agency plays the odds with every shuttle liftoff.
"If foam hits the orbiter and doesn't damage it, I'm going to say ho-hum because I know we're going to release foam. The goal is to make sure that the foam is of a small enough size that I know we're not going to hurt anything," Griffin said in a weekend interview with The Associated Press.
"It's hardly the only thing that poses a risk to a space shuttle mission," he said.
If photos during launch or the flight show serious damage to Discovery, the crew could move into the space station. Then a risky shuttle rescue — fraught with its own problems — would have to be mounted. The rescue ship, Atlantis, would face the same potential foam threat at launch. NASA also worked on a possible plan for flying Discovery back to Earth unmanned if necessary.
Many have speculated that if anything happens to Discovery or its crew, the shuttle program could end with this mission, and plans for moon and Mars exploration could be put in jeopardy.
In its flight last July, Discovery experienced dangerous foam loss, though the chunk was smaller than one that slammed into Columbia's left wing, and it missed Discovery altogether.
Just like a year ago, more than 100 cameras and radar were trained on Discovery at liftoff to spot any foam shedding. The intensive picture-taking continued with on-board cameras and the astronauts snapping zoom-in shots upon reaching orbit.
NASA figures it will be nearly a week before it can decisively say whether any debris hit Discovery during launch.
Last July, cameras caught a 1-pound (0.5 kilo) chunk two minutes after liftoff, despite extensive repairs that came after the Columbia disaster. The big piece of foam came off an area untouched in the wake of the tragedy. Smaller pieces popped off other parts of the 154-foot tank.
Over the past year, NASA has removed foam from the location of last year's largest foam loss, saying it represented the biggest aerodynamic change to the shuttle in 25 years of flight. Engineers deemed the foam there unnecessary.
Shuttle managers put off repairs to another potentially dangerous area of the tank, foam wedges to insulate the metal brackets that hold pressurized lines in place. The foam prevents ice and frost from forming on the brackets once the tank is filled with super-cold fuel.
Managers said they wanted to make one major change at a time. The space agency's chief engineer disagreed as did the chief safety officer, saying they would rather take the extra six months to fix the problem before launching.
Griffin contends NASA doesn't have time to spare with the shuttles set to be phased out in 2010.
One of the seven crew on Discovery is a German, Thomas Reiter of the European Space Agency, who will move into the space station for a half-year stay, joining the American and Russian there already.
Reiter will bring the size of the station crew to three for the first time since 2003.
Besides commander Lindsey and Reiter, Discovery is carrying pilot Mark Kelly; Michael Fossum and Piers Sellers, who will conduct at least two spacewalks at the station; and Lisa Nowak and Stephanie Wilson.
Beginning Wednesday, they will survey use a 50-foot (15-meter) inspection boom to view the shuttle for damage. They also will make repairs to the space station and deliver much-needed supplies.