CAPE CANAVERAL, Fla. – A malfunctioning fuel-tank sensor scrubbed Wednesday’s launch of shuttle Discovery. NASA said the next try would not be made until at least Saturday, though the delay could be longer.
It was the first launch attempt since the Columbia accident of February 2003.
Mission managers said a mechanical problem such as this would require at least several days to troubleshoot and repair.
In a worst case, it could require a rollback of the shuttle to its hangar. That would mean a delay of several weeks.
Wayne Hale, a shuttle program manager, said engineers would study the problem overnight and meet today to discuss it.
The absolute best case was another launch attempt Saturday, he said, but he offered no firm date for a new try.
Earlier, NASA Administrator Mike Griffin said he had some hope the mission could be rescheduled for Monday. He noted that one mission in the 1980s was scrubbed 14 times before it blasted off.
“This is nothing,” he said.
Still, if Discovery cannot be launched by July 31 on its mission to test new shuttle safety equipment and deliver supplies to the International Space Station, orbital dynamics dictate that it must wait for the next window, which opens Sept. 9 and closes Sept. 24.
The development disappointed the many thousands of spectators gathered along the fringes of the space center.
“We drove three and a half hours from Miami,” said Juliane Bahe, a biophysicist researcher at the University of Miami, but “it’s better to be safe than sorry.”
The scrub came as some astronauts were still strapping into the cockpit. White-suited technicians began helping them leave. The crew drove away from Launch Pad 39B less than an hour later.
They were in no imminent danger during the event.
“Everything is safe; they are doing a controlled exit from the vehicle,” said NASA astronaut Dave Wolf.
“This is part of being an astronaut,” said, Sen. Bill Nelson, D-Fla., who flew aboard shuttle Columbia in 1985 after four launch scrubs.
He said the quick decision to postpone launch illustrated a new appreciation at NASA for the safety of the crew.
“You can’t take the risk,” Nelson said. “You have to stop the count, go in there and take a look.
“There are 1,500 parts on the shuttle that, if they don’t work, you have catastrophe,” he said. “The culture in NASA now is that you don’t launch if things aren’t right.”
NASA spokesmen said the problem involved a “low-level fuel cutoff sensor,” one of four that are on the huge external fuel tank. They are critically important parts that make sure the shuttle’s engines shut off before they run out of fuel.
Engineers said the sensor indicated a low fuel level, even though the tank was full.
The part “for some reason did not behave today, and so we’re going to have to scrub this launch attempt,” launch director Mike Leinbach told the astronauts and the launch team.
“So appreciate all we’ve been through together, but this one is not going to result in a launch attempt today.”