Shuttle Fleet Grounded by Fuel Leaks : NASA Takes Action After Problem Also Is Found in Atlantis

The discovery of a hydrogen leak on the space shuttle Atlantis in the same area as a leak that grounded another shuttle prompted NASA today to halt all flights until the problem is corrected.

William Lenoir, NASA’s spaceflight chief, said the Atlantis, now on the launch pad, will have to be rolled back and the fuel tank removed in order to study and correct the leak.

A similar problem last month forced the shuttle Columbia off the launch pad.

With the leak now found in two of the nation’s three spaceships, Lenoir said the agency had no choice but to stop flying until it is understood and fixed.

“We can’t fly until we can get hydrogen into the tank and we’re not going to put hydrogen in the tank until we can do it safely, and we’ve got a problem getting over that hump right now,” Lenoir said in a news conference at Kennedy Space Center in Florida.

“There’s no question that we won’t fly until we understand it (the leak), have it fixed, have tested it, verified it and we’re ready,” Lenoir said.

Before the leak was discovered, NASA had hoped to launch Atlantis on a secret military mission in mid-July.

Lenoir said the leak problem could be solved in as short a time as two weeks, or it could take longer if a new design is needed for pipes and valves that control the flow of liquid hydrogen into the space shuttle’s fuel tank.

The shuttle’s main rockets burn a propellant of hydrogen and oxygen. Both chemicals are pumped into an external tank in a very cold liquid form.

Lenoir’s announcement came after engineers conducted a hydrogen loading test on the Atlantis. A leak was found within minutes.

The leak check was ordered as a precaution after a similar hydrogen leak stopped the countdown for the shuttle Columbia six hours before its intended launch May 30. Columbia is now grounded until at least mid-August.

The test, involving pumping up to 200,000 gallons of liquid hydrogen into Atlantis’ giant external tank, was intended “to establish confidence in the hardware,” NASA spokeswoman Lisa Malone said.

Malone said a concentration of hydrogen was found near a four-inch disconnect valve in the area of a 17-inch-diameter valve, the same that appeared responsible for the leak that grounded Columbia.