Shuttle Scrubbed Until Next Week

NASA Says Late Next Week Is Earliest Possible Launch Time

(CBS/AP)  A NASA spokesman tells CBS News a shuttle launch attempt won't take place until late next week at the earliest.

The space agency is backing out of the countdown and has given up trying to make a launch attempt anytime soon, said spokesman Bruce Buckingham.

Mission managers expected to meet later in the day to plot their next strategy and settle on a target launch date.

Deputy shuttle program manager Wayne Hale said the space agency still probably faces several days of troubleshooting to figure out what caused the faulty fuel-gauge reading that forced the cancellation of Wednesday's launch attempt.

To find the problem, CBS News Correspondent Bob Orr reports, NASA officials are “starting inside the belly of shuttle itself and working toward the fuel tank in an inch-by-inch search for the culprit.”

Hale said the space agency had 12 engineering teams around the country trying to figure out the problem. But engineers still aren't sure why the fuel sensor read full when it should have read empty.

“I wish I had more answers for you,” Hale said.

CBS News Correspondent Stacy Case reports a faulty sensor could cause the fuel tank to shut off too early or too late. Either could be catastrophic.

“If they suddenly spun up with no fuel there, you'd almost certainly have what they call ‘uncontained fragmentation,’” reports CBS News Space Consultant Bill Harwood. “That's NASA-ese for an explosion.”

Hale wouldn't rule out the chance of launching Discovery in July. NASA has until the end of the month, or it must wait until September. The launch windows are dictated by both the position of the space station and NASA's desire to hold a daylight liftoff in order to photograph the spacecraft during its climb to orbit.

“I'm not ready to give up on a July window,” Hale said. “We still have several days ahead of us.”

Given the elusive nature of recent, still-unresolved problems with the so-called engine cutoff — ECO — sensors and their associated electronics, a quick fix would seem problematic, reports Harwood.

"It's so far an unexplained anomaly," said NASA administrator Michael Griffin. "When we can explain it we will."

"Unexplained anomalies are the worst ones," said Hale. "What you'd really like to do is find the problem and fix it. So when you have a problem that kind of comes and goes and you can't put your finger on it, that's a tough issue."

There have been problems with the fuel sensor system before. Sensors also failed in a tank test done in April. It's unclear if the problem is with the sensors themselves or the system which channels the information to the craft's computers.

It's baffling, says Harwood.

"It's kind of like 'I have an engine light in my car that comes on every now that I don't know what causes it, neither does my mechanic," he said on CBS News' The Early Show (video). "It's a hard thing to track down ... it's a real detective story."

But, until engineers figure it out, Discovery is going nowhere.