CAPE CANAVERAL, Fla. – Despite lingering concerns about insulating foam falling from the shuttle’s external fuel tank, NASA set off the biggest fireworks display of all yesterday, successfully launching Discovery and its seven astronauts on a mission to the International Space Station.

“I can’t think of a better place to be on the Fourth of July,” shuttle Commander Steven Lindsey said, minutes before launch. “We hope to give you an up close and personal look at the rocket’s red glare.”

Discovery blasted off at 2:38 p.m., propelled into space on a bright cone of fire that competed with the summer sun.

The shuttle’s two 149-foot-long solid rocket boosters and its three main engines drove the 4.5 million-pound shuttle into orbit in a little more than eight minutes.

The mission is the second and final test flight of the shuttle as the space agency recovers from the Columbia disaster in 2003. A falling piece of foam was blamed for damaging the craft, which broke up on re-entry, killing all seven of its crew members.

The only troubling part of Discovery’s launch occurred when several pieces of debris floated away from the massive external fuel tank almost three minutes into the ascent. More debris came off the tank two minutes later and hit the underside of the craft.

Space shuttle managers said that even if all the debris were pieces of foam, they would not pose a threat to Discovery. The first incident occurred when the shuttle was 240,000 feet above Earth, where the air is so thin it would not be capable of accelerating debris to a damaging speed.

The crew also reported seeing something about 6 to 8 feet long drift away from Discovery. They thought it might be insulating material used on the side of the craft. The material has come off in the past, but that amount would be highly unusual.

NASA engineers guessed it was probably ice, not insulation.

The shuttle program manager, N. Wayne Hale Jr., said the evidence, so far, does not point to trouble. “What we’ve seen so far is very encouraging,” he said.

Mr. Hale said it would be at least three days before all the data and camera images are downloaded and studied, at which time NASA would be able to determine if there is anything to worry about in bringing Discovery home after its 12-day mission.

Despite those worries, the feeling among NASA management was celebratory following the launch.

“We had a great day,” said John Shannon, chairman of the shuttle mission management team, which gave the go-ahead for launch yesterday following several days of bad weather, along with several technical problems that threatened to delay the mission.

Discovery is carrying two tons of provisions for the space station and an equally heavy load of expectations and anxieties.

The hopes were that with a problem free flight, the wounded American space program could get back on the fast track of space exploration.

“Now is the time to pick up the normal … tempo and get about our business,” the NASA administrator, Michael Griffin, said. That business is completing construction of the International Space Station, which remains half-built and in limbo since the Columbia accident. The shuttle is scheduled to dock with the space station tomorrow.