Glass in the Tank Linked to Shuttle Leak

Tiny glass beads that somehow got into a fuel line are believed to have caused a hydrogen leak that grounded the space shuttle Columbia in May, a NASA official said.

Workers discovered between 100 and 200 glass beads between one-thousandth and three-thousandths of an inch in diameter inside a piece of equipment found leaking on the shuttle, said William Lenoir, associate administrator for space flight.

The beads were found about two weeks ago when the leaky piece of equipment, a so-called disconnect assembly used to mate the shuttle to its external fuel tank, was sent to the Parker Hannifin Corp. in Irvine, where it was made, Lenoir said.

The beads could have gotten between a shaft in the disconnect assembly and a seal that prevents the hydrogen fuel from leaking, causing the problem, Lenoir said.

Officials are uncertain how the beads could have gotten into the disconnect assembly but were working with the company to find out, he said.

The only clue so far was that the beads were used at the company for other purposes when the disconnect was made in 1986, he said. The beads are used for a variety of manufacturing processes, he said.

“There’s not much question in our minds that that’s implicated in why did the external tank disconnect shaft seals leak. We’ve been unable to find definitively how they got there,” he said.

“In a way that’s good news because that says, ‘Hey, there’s some external something contamination that led to the leak.’ And we just need to make sure we don’t have that (in the future),” he said.

The shuttle Columbia, which has been fitted with a new disconnect mechanism, is scheduled to blast off from the Kennedy Space Center in Florida on Sept. 1 for a nine-day astronomy mission that was postponed by the leak in May.

“We’ve done everything we could think to do to increase the probability of launching,” Lenoir said.

The shuttle Atlantis, which was grounded by a hydrogen leak in July that resulted from an unrelated problem, is currently undergoing repairs. That delay postponed a secret military mission.