Shuttle Scrubbed Until Next Week
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
. "It's a hard thing to track down ... it's a real detective story."But, until engineers figure it out, Discovery is going nowhere.
The seven-astronaut crew had already climbed aboard the shuttle Discovery Wednesday when NASA halted the countdown with just 2½ hours to go, scrubbing the first shuttle flight since the 2003 Columbia tragedy.
Astronaut Cady Coleman has been in that position.
"You're just really disappointed, and yet, I think probably your second thought is for your friends and family that came to this launch," Coleman told
. "You're still going to go ... but your friends and family have bought plane tickets and hotel rooms and vacation time, and you're going to hear about all of that when you get home from this great trip!"The disappointment came just a day after an embarrassing turn for NASA, when a plastic cockpit window cover fell off the shuttle and damaged its fragile thermal tiles before the spacecraft had even taken off.
From Cape Canaveral, where congressmen and astronaut families had come to witness the awe-inspiring sight of a rocket launch, to museums across the country where schoolchildren had gathered, the delay of the long-awaited return to space was disheartening.
"I wanted to see it really, really, really bad," groaned 8-year-old Michael Schamtin of Sherwood, Ore., who had waited for liftoff at the Oregon Museum of Science and Industry.
Thousands of people had descended on the space center for the launch, including John Glenn, the first American to orbit the Earth, members of Congress, and family members of the seven fallen Columbia astronauts. Lawmakers and others refrained from second-guessing NASA's decision to press ahead before it had gotten to the bottom of the fuel gauge problem.
"I'm disappointed for all of us," said Sen. Bill Nelson, D-Fla. But he added, "The system is working like it should."
"The significance of the scrub on this particular mission is showing that they're doing it right," former astronaut Kathryn Thornton told CBS News. "They want the vehicle to be in as good a shape as it can be before they launch."
The fuel depletion sensors are a critical safeguard against potentially catastrophic failures.
"They're there to protect us in case we run out of gas," Hale said. "Now we don't plan to run out of gas. As a matter of fact, we launch with some fairly comfortable propellant reserves in the external tank to allow for dispersions that might happen within the launch phase. So you have to have something go wrong to really need these sensors. That's the first thing you really need to understand."
"They're kind of a safety net for other systems on board, and they have a flight rule that says all four of these sensors have to be working before you can continue the countdown and launch," said Harwood.
Asked if NASA might amend the flight rules to get Discovery off the ground, Hale said: "The answer to that is no. Every time we have reviewed the rules, we've come to the same conclusion. They're in place for good reason."