Friday, July 29, 2005

NASA: Nothing Changed

Turns out that nothing at NASA really changed after the loss of Columbia and her crew. In spite of the hard work of Admiral Hal Gehman and the Columbia Accident Investigation Board (CAIB), NASA still has a concept of "acceptable risk" that is at odds with the facts:

NASA's engineers knew that the foam insulation around the space shuttle's giant external fuel tank was a problem. They were particularly worried about any hand-sprayed sections, like the foam that broke off and fatally damaged the Columbia in 2003.

But after spending millions of dollars, reviewing foam losses from dozens of flights and conducting five million computer simulations, engineers decided that a hand-sprayed foam ramp on the tank was an "allowable," a risk that was too unlikely to pose a danger to the shuttle.

"We had enough data that showed we had had very few problems with the PAL ramp," said William W. Parsons, manager of the shuttle program.

In fact, they had little data. Many tanks, post-launch, were not photographed well, leaving it a mystery as to whether foam had come off and where. The fact is, it turns out the PAL ramp foam is as dangerous as the bipod ramp foam, and had the piece shed from Discovery's tank on ascent come off earlier, it might have ripped a hole in the orbiter's leading edge similar to what destroyed Columbia. The nasty fact is, none of the foam problems have been solved at all. Photos of Discovery's tank show not only the loss of one of the PAL ramps, but considerable "popcorning" of acreage foam as well, where small pieces pop off and leave divots in the remaining foam. Popcorning can and has damaged orbiter bottom tile on previous flights; fortunately the tile is more resilient to damage than the RCC on the leading edge of the wing. From NASA, dumbass excuses like this:

Aldo J. Bordano, a retired NASA aerosciences division chief who was on a peer-review panel that studied the agency's analysis of the external tank and foam, said the panel believed that there should have been more physical testing of the external tank's vulnerable components before flying.

"We would have liked more hardware testing," Mr. Bordano said yesterday in an interview, "but that would have added another year to the delay. Ideally, you would want to be able to take a tank and actually put it through some kind of testing like what happens through the ascent phase and see if it hangs together."

I'm sorry, but two years is plenty of time for such testing. After the Apollo capsule fire, the capsule was completely redesigned and flying again in about a year - and the Apollo capsule was a much more complex item than the simple external tank. More stupidity:

The external tank used on this flight of the Discovery was one that had been assembled and sprayed before the loss of the Columbia and the flurry of reviews and changed practices, said June Malone, a NASA spokeswoman.

Amazing. As usual, NASA was forced to do this on the cheap, and the result was not particularly surprising. There will be more inspections of the orbiter today; God knows what the results will be, since every time NASA opens its mouth the situation gets nastier:

NASA said Thursday that Discovery escaped damage from the potentially deadly chunk of foam insulation that broke off from the fuel tank, but may have been struck in the wing by a much smaller piece. Even if the small foam fragment did hit, engineers believe the impact caused no damage of concern, Hale said.

Yes, that's what they thought last time. We trusted NASA to fix this. So did the astronauts, and the members of CAIB. This is going to get ugly.


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