NASA said on Wednesday evening it will suspend future space shuttle flights because foam debris that brought down Columbia is still an unsolved problem.

Shuttle managers made this decision after a large piece of foam insulation broke off from the shuttle Discovery's fuel tank during its liftoff on Tuesday.

"We won't be able to fly again" until the problem is solved, said shuttle program manager Bill Parsons at a briefing in Houston space center.

Although NASA shuttle managers did not think the foam had hit Discovery, they admitted to have underestimated the insulation problem.

Before the Discovery launch Tuesday morning, NASA believed the safety of its shuttle fleet had been improved.

"Clearly, with the event we had, we were wrong," said Parsons,"Until it is closed we will not fly again. Might as well let that out now. Until we are ready we will not fly again."

Engineers said the foam might be 50 to 60 centimeters long, 20 to 30 centimeters wide, and just a few centimeters thick, very similar to the chunk that hit Columbia's left wing during liftoff in January 2003.

Meanwhile, the Discovery crew are observing the shuttle external tank, wings, and nose with digital cameras and laser scans, to determine whether the shuttle had been hit by the foam insulation, a NASA shuttle status report said.

The crew also photographed the Orbital Maneuvering System pod tile areas and sent back images. Most of the heat shield survey, taking a close look at the reinforced carbon-carbon of Discovery's wings and nose was sent down live, NASA said.

Source: Xinhua