NASA managers celebrated the success of the nation's first Fourth of July manned shuttle launch, saying they were not worried about a small piece of foam that broke off and hit the Discovery during its ascent.
"They don't get much better than this," NASA Administrator Michael Griffin said of the launch.
Griffin chose to go ahead with the mission 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.
The shuttle's astronauts planned to give the spacecraft a more thorough physical examination from space Wednesday, the second day of their 12-day mission. The day began with some good news for the astronauts, when mission managers allowed them to sleep in half an hour past their planned 4:40 a.m. EDT wakeup time.
They were to take images of the shuttle's wings and nose cap with a camera and laser attached to a 50-foot boom, which itself would be affixed to the shuttle's 50-foot robotic arm.
The Day 2 inspections were implemented after the Columbia disaster, in which foam from the shuttle's external tank struck the orbiter's wing, allowing fiery gases to enter the spacecraft during descent in 2003. All seven astronauts were killed.
Last year's Discovery crew was the first to try out the new inspection techniques which can detect damage as small as an eighth of an inch. The current crew will only be the second to conduct such inspections.
"We can detect very, very small damage indeed," said Wayne Hale, shuttle program manager.
Shuttle managers said early video images of liftoff showing small pieces of foam breaking away - and one striking the spacecraft - were not troubling.
"The tank performed very, very well, indeed, very pleased as opposed to where we were last year," Hale said Tuesday night, five hours after liftoff. "We saw nothing that gives us any kind of concern about the health of the crew or the vehicle."
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.
Discovery blasted off from its seaside pad Tuesday at 2:38 p.m EDT.
About three minutes later, as many as five pieces of debris were seen flying off the tank, and another piece of foam popped off a bit later, Mission Control told the crew. The latter piece struck the belly of Discovery, but NASA assured the seven astronauts it was no concern because of the timing.
Hale said Discovery was so high when the pieces came off that there wasn't enough air to accelerate the foam into the shuttle and cause damage.
All but one of the foam pieces were small and all came off well after the two-minute, 15-second point where they can still cause damage, Hale said. NASA had expected minor foam loss.
The astronauts reported seeing what they described as a large piece of cloth tumbling away from Discovery soon after reaching orbit. It looked like one of the thermal blankets that protects the shuttle, they said, but Mission Control told them it was likely ice and that a similar observation was made during Discovery's flight a year ago.
"Wow, that's real good news," said shuttle commander Steven Lindsey. Hale later confirmed it was ice.
The mission for Discovery's crew is to test shuttle-inspection techniques, deliver supplies to the international space station and drop off European Space Agency astronaut Thomas Reiter for a six-month stay. Astronauts Piers Sellers and Mike Fossum plan to conduct two spacewalks, and possibly a third one, which would extend the mission by a day.
Lindsey, an Air Force fighter pilot, was at Discovery's controls and aiming for a Thursday linkup with the international space station.
"I can't think of a better place to be here on the Fourth of July," radioed Lindsey.