I know very little about what happened (even less than many of you, probably), because I just got up and heard the news. I got a phone call this morning from a friend on the east coast.
Like Challenger, this was not a survivable accident. There is no escape system in the Shuttle, for sound engineering reasons.
First my condolences to the friends and family of the crew, and to the nation of Israel, which has suffered so much during the past few years. It has to be a tremendous blow.
I hate to talk about good news/bad news in a situation like this, but let’s just say that it could have been worse.
In the “it could have been worse” category, of all the vehicles to use, Columbia was the least valuable, because it was the oldest in the fleet, and the heaviest. For this reason, it was rarely used for ISS missions, because its payload capability was much less (which is why it was being used for this non-ISS mission).
Also, at least the mission was completed before it happened.
Because it was the oldest bird, if it happened as a result of a simple structural failure (e.g., keel or spar), that would have been the most likely vehicle to which it would occur. On the other hand, that would only explain it if it were a consequence of age. If it’s cycle fatigue, I’d have to go look it up, but I don’t know if Columbia had more flights under its belt than the rest of the fleet.
WARNING: RAMPANT SPECULATION AHEAD
Here are the possibilities off the top of my head.
Terrorism: possible, but unlikely. If it were, it was a result of sabatoge–not being shot down. It would be difficult for us to take out such a target under those conditions (though the missile defense system under test could probably do it). No one else has such a capability, as far as I know. If it were sabatoge, it could have been something done to the vehicle before it left the ground, either a pressure-sensitive detonation (e.g., something that arms itself when it goes into vacuum, and then goes off when it senses atmospheric pressure again). This seems too sophisticated for Al Qaeda. It could also be simply sawing through the wing spar before the flight, because most of the stress on that member occurs during entry.
Failure of TPS: It could be that it lost some tiles during ascent–sometimes ice falls off the ET during launch, and it could have taken some out in a critical area, perhaps along the leading edge of the wings. Since this flight didn’t go to ISS, no one would have necessarily seen the damage from outside the Shuttle. This would result in burnthrough of a wing, which would quickly propagate through and then tear it off, after which the vehicle would break up from aerodynamic pressure.
I just heard the CNN announcer say that the airframe was “certified” for a hundred missions. Certification is not really the right word. “Designed to meet the requirement of” would be more accurate. Certification would imply that we had sufficient experience with such things to know that it was really capable of that, and we simply don’t.
Next theory, as I already mentioned would be structural failure due to age or cycles. I think that the primary structure is aluminum (though the spar and keel may be titanium–I don’t recall for sure). I wouldn’t think that this is a likely failure, but it’s certainly possible.
The last one I can think of (other than alien attack), would be a loss of the attitude control system (either the flight computers, or an RCS valve stuck open, or an actuator problem on a control surface) which would result in a bad orientation, which again could cause aerodynamic breakup.
OK, one more. Somehow the hypergolics in the OMS/RCS system mixed and caused an explosion.
All of these seem unlikely, but it’s probably one of them.
What does it mean for the program?
Like Challenger, it was not just a crew that “looked like America” (two women, one african american) but it also had the Israeli astronaut on board, which will have some resonance with the war.
Instead of happening just before the State of the Union, it occured three days after. It also occured two days before NASA’s budget plans were to be announced, including a replacement, or at least backup, for the Shuttle.
The fleet will certainly be grounded until they determine what happened, just as occurred in the Challenger situation. Hopefully it won’t be for almost three years. If it is, the ISS is in big trouble, and it means more money off to Russia to keep the station alive with Protons and Soyuz. The current crew can get back in the Soyuz that’s up there now. They will either do that, or stay up longer, and be resupplied by the Russians.
The entire NASA budget is now in a cocked hat, because we don’t know what the implications are until we know what happened. But it could mean an acceleration of the Orbital Space Plane program (I sincerely hope not, because I believe that this is entirely the wrong direction for the nation, and in fact a step backwards). What I hope that it means is an opportunity for some new and innovative ideas–not techically, but programmatically.
Once again, it demonstrates the fragility of our space transportation infrastructure, and the continuing folly of relying on a single means of getting people into space, and doing it so seldom. Until we increase our activity levels by orders of magnitude, we will continue to operate every flight as an experiment, and we will continue to spend hundreds of millions per flight, and we will continue to find it difficult to justify what we’re doing. We need to open up our thinking to radically new ways, both technically and institutionally, of approaching this new frontier.
Anyway, it’s a good opportunity to sit back and take stock of why the hell we have a manned space program, what we’re trying to accomplish, and what’s the best way to accomplish it, something that we haven’t done in forty years. For that reason, while the loss of the crew and their scientific results is indeed a tragedy, some good may ultimately come out of it.
I’m driving back down to LA today, but I’ll have some more thoughts this evening or tomorrow, particularly as more details emerge.
[Quick update before I leave, about 9:25 AM]
Someone in the comments section asks if the vehicle will be replaced. No, that’s not really possible-much of the tooling to build it is gone. It would cost many billions, and take years, and it’s not really needed at the current paltry flight rate. Assuming that they have confidence to fly again after they determine the cause, they’ll continue to operate with the three-vehicle fleet, until we come up with a more rational way of getting people into space, whatever that turns out to be. Unfortunately, because it’s a government program, I fear that the replacement(s) won’t necessarily be more rational…
[One more update at 9:49 AM PST]
Dale Amon has posted on this as well. To correct a couple of statements regarding me, however–I’m arriving in LA tonite–I’m leaving San Bruno this morning, and driving down.
And I never worked on the Shuttle directly. I worked for Rockwell, but in Downey, not Palmdale, and on advanced programs and Shuttle evolution, but not on the main Shuttle program itself.
[OK, one one more before hitting the road, at 10 AM]
Donald Sensing says in the comments:
I have read and respected this blog as long as I’ve been blogging. But today, Rand, I am sorry to say you blew it: “. . . but let’s just say that it could have been worse” and etc.
I just don’t give care about all that. This kind of “analysis” is not relevant at this point. It doesn’t matter. This is a human tragedy in which seven brave men and women violently died.
The social context of these deaths, and the publicly spectacular manner of their deaths, raise the tragedy beyond the personal to a different level. This sad event is a “meta-event,” whose significance is not quantitative (seven dead) but qualitative, striking close to the core of certain aspects of the American national identity. So it does not matter that Columbia was the oldest, or that its mission was completed (and the mission’s cost money wasn’t wasted) and all the rest. At least, it does not matter now, and it may not ever matter, even to NASA. The human scale of the tragedy far outweighs the technical scale.
Donald, thanks for the comments, but with all due respect, I disagree, and that kind of attitude is exactly why the manned space program has been such a disaster for so long. As long as we elevate the humans over the hardware, and emotions over rational discussion, we will never make significant progress in this frontier.
People die on frontiers, (and even in non-frontiers–more died in traffic accidents in the past twenty-four hours than have died in space since we first started going there) and if we can’t accept that, then we have no damned business being there.
I’ll expand on that in a post later this weekend. In fact, it may be the subject of a (perhaps coldhearted, to some) Fox column.