Discovery's fuel tank "performed very well" during the shuttle's launch Tuesday, shedding small pieces of debris as expected without endangering the astronauts, a top NASA official said.
"The tank performed very well this time," space shuttle program manager Wayne Hale told reporters five hours after the 2:38 pm (1838 GMT) liftoff at the Kennedy Space Center in Cape Canaveral, Florida.
He added that there was no reason to have "any concern" for the safety of the seven astronauts heading to the International Space Center (ISS).
"We don't seen any concern for the orbiter," Hale added.
About five pieces peeled off the fuel tank a few minutes after the launch, at a time when loose debris would not threaten the shuttle, he said.
"This is a great improvement," Hale said.
All but one piece were also too small to pose a risk, he added.
He said it was too soon to determine whether the debris were ice produced by the tank's supercold propellant or the foam insulation that had pierced Columbia's heat shield three years ago, dooming the shuttle.
He noted that the ISS crew will take pictures of Discovery's heat shield to check for any damage.
NASA spent more than a billion dollars to fix the problem after the Columbia accident, only to see foam shed from Discovery's fuel tank last year during the first post-tragedy launch.
