Why NASA's making the right decision

The same mindset exposed American astronauts aboard the Russian Mir space station to a sequence of near-death experiences, from fires to collisions to end-over-end out-of-control tumbling, as NASA officials kept telling themselves that “there is no current evidence that Mir is unsafe,” without ever asking how they would be given such evidence if the Russians didn’t want them to see it.

But the day-and-night difference in safety decision-making is now being illustrated by the challenge of getting Discovery, and the entire space shuttle program, back into space. If troubles return with the persnickety sensor, NASA officials have developed well-defined and well-thought-out options for deciding which of the problems will not threaten flight safety, and which might.

Inside view
Documents provided to MSNBC.com detail the reasoning and the technical background of the decision made July 20 after “healthy debate” at the Mission Management Team meeting at Cape Canaveral. The meeting was opened with a wry remark that it was the thirty sixth anniversary of the first moon landing, and NASA was still struggling to get back into low Earth orbit.

Experts agreed that the leading theory of the glitches — spurious signals leaking into the box through bad electrical "grounds" — could not be categorically proven, and there wasn’t even uniform agreement. Cleaning up the ground was deemed “mandatory” to fly.

An hour was spent on considering the differences between the likelihood of multiple failures caused by a generic design flaw versus failures caused by a single common cause (such as power loss). This in-depth discussion laid the groundwork for estimating the odds of a second sensor problem, based on the possibility of a single problem occurring.

All the hazards associated with additional testing were balanced against what might be found out (“Don’t worry about what the press may say,” an official advised), and a consensus emerged that proceeding directly to a launch attempt was safest. A detailed plan on what to do in case of new failures was then drawn up.

In the final hours of the countdown, that plan will be put into operation. These internal documents show it to be a mature, well-founded strategy, not a "by-guess-and-by-golly: mindset with "full-steam-ahead" attitudes.

It’s the only way to fly this mission, and to fly a rescue mission if this crew does wind up stranded on the space station, and to fly the remaining space shuttle missions as the aging vehicles show more and more quirkiness of old age. It’s the only way to fly if there’s any hope of avoiding the judgment flaws that have already killed far too many astronauts.

James Oberg, space analyst for NBC News, spent 22 years at the Johnson Space Center as a Mission Control operator and an orbital designer.

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