NASA's Shuttle Strategy

Bill Harwood On Preparations For Discovery's Launch

(CBS)  This article was written by CBS News Space Consultant Bill Harwood

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The shuttle Discovery was cleared for launch Tuesday after senior managers agreed on a strategy that would permit liftoff even if - and only if - the shuttle experiences a fuel sensor problem like the one that grounded the ship July 13.

That strategy, built around the agency's willingness to consider relaxing a long-standing launch rule to get around the fuel sensor problem, has raised eyebrows in some quarters and questions about whether safety is taking a backseat to schedule pressure and "go" fever.

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If the shuttle Discovery launches as planned Tuesday, CBS News will have live television coverage beginning at 10:30 a.m. ET. CBSNews.com will also have a live Webcast of the launch and preparations all morning.

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NASA managers insist their approach is based on sound engineering and even though the sensor problem remains an "unexplained anomaly," exhaustive testing has convinced the community the problem is not a generic safety-of-flight issue.

Wayne Hale, chairman of NASA's mission management team, put it like this: "I wake up every day and I ask myself are we pushing too hard, are we doing this thoroughly, have we done the right technical things, have we asked the right people, have we built the tests properly?

"I think we're all still struggling a little bit with the ghost of Columbia and therefore we want to make sure we do it right," Hale said Monday. "Based on the last 10 days worth of effort, the huge number of people and the tremendous number of hours that have been spent in testing and analysis, I think we're coming to the right place."

NASA Administrator Michael Griffin agreed, saying "I've delved into this situation as thoroughly as my intellect permits. And I'm quite comfortable with where we are. ... Even if (a sensor failure) does recur, we're still two-failure tolerant, so it's not a safety of flight issue."

Asked if he was concerned about any public perception that NASA has "launch fever" and was not giving the sensor issue the attention it might deserve, Griffin said, "I think what you want coming out of the Columbia accident and the loss of Columbia and the soul-searching examination that NASA has undertaken since then, what you want of NASA is that we make the right technical decisions, that we do the right thing to the extent that we can figure that out. Which is hard."

"We can't restrict the range of our options to those things which are going to present well. We have to figure out the right thing and try to do that and then work hard to try to explain to you why it is the right thing. And these are rather arcane matters, I would admit. They're rather difficult. And sometimes they don't always present well. (But) you want us doing what's right, not what's necessarily obvious or popular," Griffin said.

NASA hopes to launch Discovery at 10:39 a.m. Tuesday, weather permitting, on a flight to service and resupply the international space station. If the shuttle is not off the ground by July 31 or Aug. 1, the flight will be delayed to September.