Fuel Leak Postpones Shuttle Launch

A leak of highly flammable hydrogen fuel at the launch pad forced NASA to postpone space shuttle Atlantis’ liftoff Thursday until Sunday at the earliest.

The fuel spewed from a broken pipe for a minute, but the white cloud dissipated and did not pose any danger, launch director Mike Leinbach said.

The pad already had been evacuated for the hazardous fueling operation, and the shuttle was dozens of feet from the leak. The seven astronauts were hours from boarding Atlantis and had not begun to suit up.

“We didn’t ever consider this a threat to the vehicle,” Leinbach said.

NASA officials said Atlantis’ liftoff on a space station construction mission will be delayed until at least Sunday so the leak 37 feet above the pad can be repaired. Atlantis had been scheduled to lift off Thursday afternoon with the newest piece of the space station: an elaborate 44-foot girder.

An engineer spotted the leak and the fueling was immediately halted about an hour after it had begun.

A weld on the 16-inch-diameter aluminum pipe cracked, apparently from the shock of cold fuel, Leinbach said. The pipes and their welds date to at least the 1980s, and age is believed to have contributed to the problem.

Technicians will put a clamshell-like clamp over the quarter-inch crack, which covers almost the entire circumference of the pipe. NASA will not inspect other welds in the line, Leinbach said.

“This mobile launcher has gone through 80-some tankings and has performed perfectly fine, so we do not feel we have a generic problem with all of our welds out there,” he said.

The leak did not occur in the plumbing that feeds liquid hydrogen into the shuttle’s big external tank but in a line that vents fuel vapors from the tank, making it easier and quicker to make repairs, NASA officials said.