NASA will hold off launching any more space shuttles until it understands why strips of insulating foam peeled off the fuel tank used by shuttle Endeavour, the U.S. space agency shuttle program manager said on Thursday, Reuters reported.
Endeavour arrived safely in orbit after Wednesday's liftoff from the Kennedy Space Center in Florida though video and images of the launch showed about a dozen pieces of debris flying off the fuel tank during the 8.5-minute climb to orbit.
Some smashed into the ship's heat shield, though NASA does not believe they caused any serious damage.
"We're not worried about this one, but we need to understand what's going on for the next flight," shuttle program manager John Shannon said at a news conference.
"This is new," Shannon said. "I don't know if we have a material issue or a process issue but we'll get to the bottom of it and clear it before the August flight."
He told Reuters in an interview that no new shuttle launches would take place until the foam loss problem was understood.
NASA has seven more shuttle launches planned to complete construction of the International Space Station. Its next flight is targeted for launch on August 18.
The U.S. space agency has been concerned about foam shedding from the tank since losing shuttle Columbia in 2003. A debris impact during Columbia's launch breached the ship's heat shield, which caused the shuttle to break apart as it flew through the atmosphere for landing. Seven astronauts died in the accident.
NASA redesigned the tanks to stem foam loss and implemented new procedures and equipment to check for damage after launch.
The images of Endeavour's launch showed patches of metal where thin strips of foam had peeled away from a part of the tank that previously had not been a problem, Shannon said.
"We have a bit of a mystery," Shannon said at the news conference. "It's from an area we don't typically expect to see foam to be lost."
The foam loss occurred relatively late during Endeavour's climb to orbit so that there was not much atmospheric force to slam debris into the ship and cause damage. If the foam had fallen off earlier during ascent, it could have been another story.
"It did not hurt us, apparently, on this flight, because it came off so late. But we'll need to understand that before the next flight," Shannon said.
A variety of tests are planned to determine if the problem on Endeavour's tank was an isolated incident or if there is a more generic issue.