Friday, April 11, 2003

Columbia Conclusions

Well, the Columbia talk was really good (despite the person behind me with the annoying cell phone and the small child somewhere in the audience who seemed to think she was supposed to be the one delivering the speech). The speaker, James Oberg was a NASA engineer for 22 years and is currently the space consultant for ABC news, so the guy definitely knows what he's talking about. He also had really up-to-date information; he said, in fact, that he'd had to replace one of the slides only two hours before as new information came in (though I don't know which one it was). I'd only been following the investigation very sporadically, I admit, so it was really great to have everything that's been learned and done so far laid out for us and put into its proper context.

It's weird the sort of mixed feelings something like this can evoke. On the one hand, there's something tremendously exciting about the scientific detective story that is the Columbia disaster investigation. Oberg calls it "forensic physics," the putting together of a zillion tiny clues and careful application of the laws of physics in order to determine what happened. Here's an example: By piecing recovered tiles together like a jigsaw puzzle, engineers were able to figure out which tiles much have come from which parts of the shuttle. By looking at where those tiles landed along the debris trail, they could tell that the left wing had broken up before the right one, since its remains were farther to the west. Now, OK, I imagine it might be pretty darned tedious to do a job like that, but I find it utterly fascinating to hear about it. Another great example: Mass and velocity calculations gave a very good prediction as to where one of the shuttle's recording devices should have landed. Search crews failed to find it, but the scientists were so convinced their equations were right that they sent the searchers back for a second look and, lo and behold, there was the recorder, still bearing readable and potentially useful data. Again, regardless of the context, I can't help but find that kind of scientific problem-solving really, really cool.

The emotional flip side to that, of course, is the incredibly saddening and sobering reason why this investigation has to be done in the first place. What's especially saddening is that, according to Oberg, there's no reason in the world those seven people had to die, if only the problem -- or rather the possibility that there might be a problem, which was all that was known at the time -- had been acknowledged. If it had, all that ingenuity could have been bent on salvaging the situation instead of on analyzing it afterwards.

It seems this particular shuttle mission was not, according to by-the-book rules, equipped for spacewalks, as it wasn't carrying any of the jet packs that are used to maneuver on EVAs. It did have the suits, though, for use in the event that the bay doors got stuck and someone might have to pop out and close them manually. So someone could have gone out and checked for damage, even without a jet pack unit. Hell, they could have built a ladder -- out of duct tape and rolled up flight manuals! -- and climbed down onto the wing to get a look at it. This sort of thing has been done before, apparently. Barring that, they could have stuck somebody in a suit, shoved him off without a pack, let him take pictures, then swung the shuttle back around to pick him up. Tricky, but apparently doable. Even if they'd actually seen the damage, of course, they might very likely have been unable to repair it, but at least they would have known better than to attempt re-entry. The astronauts, if not the shuttle itself, would most likely have been recoverable. True, it wouldn't have been possible to get another shuttle prepped and launched before Columbia's air became unbreathable (due not to a lack of oxygen, by the way, but to an overabundance of carbon dioxide once the atmospheric scrubbers had reached their capacity). And a Russian rescue mission was out of the question; the orbital dynamics just wouldn't have worked. But, as Oberg points out, there are other rockets in the world. There was a French rocket ready and set to launch. Pay the French enough money, and you could bet they'd be willing to sell you the rocket. Fill it with fresh atmospheric filters, food, and whatever other supplies the astronauts would need to hold out until the next shuttle was ready, let Columbia use the fuel it isn't going to need for re-entry to maneuver around and pick up the supplies, and you're set. It's the stuff heroic Hollywood movies are made of.

But none of that happened, of course, because the problem wasn't recognized as a problem, at least not at the level where the actual decisions get made. After the piece of foam fell off the fuel tank and hit the wing, the before-and-after photographs of the shuttle's underside were carefully scrutinized, and, well, nobody saw any damage. (It now appears that the reason for that may have been that the hole was on the black part of the tiles. Hmm, black hole on black tile against a black background... Gee, I wonder why that wasn't visible?) So they proceeded to apply the old logical fallacy that "absence of evidence is evidence of absence," labelled it "not a safety concern," and ceased to worry too much about it. In a way, this is actually quite understandable. It's part of human nature, really: unless you've got hard, solid evidence that something's seriously wrong, it's simpler (and, let's face it, often correct) to assume that everything's fine. But, as my mother used to say (often enough to be really annoying): "assume" makes an ass out of u and me. And in a hostile and largely untested environment like outer space, you simply can't afford to ignore even the smallest hint that something might be wrong. This sort of thing has happened before, too. Oberg cites not just the infamous O-rings of Challenger (assumed to be safe for untested low temperatures simply because there was no evidence to the contrary), but also the near-catastrophic unaddressed safety issues aboard Mir and the ill-fated Mars Pathfinder mission (in which he claims that people who noticed some suspicious oddities in their data were essentially told, "Well, you don't know the spacecraft's off course, so we're not going to do a course correction unless there's a better reason to think it's necessary" shortly before the probe became intimately acquainted with the Martian landscape in a fashion that did neither it nor us any good). His conclusion is that while increasing safety features on the shuttle is a good thing -- they're talking about including tile repair kits and doing visual inspections of shuttles from the International Space Station, among other things -- the most important lesson to take away from Columbia is that it's this complacent attitude that has to change. You should assume, he says, that space is trying to kill you and act accordingly.

Makes a lot of sense to me.

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