the space shuttle

So Columbia disintegrated on reentry. Unbelievable. I was watching this on TV almost from the moment it was first reported, and I couldn't believe how long it took them to come up with possible "scenarios" under which this could have happened. Time now has a short report on those online. It rightly debunks the ridiculous thought that this could have been a terrorist attack, as some news channels were suggesting:

There are three possible scenarios that explain this event. The first, which I believe is the likeliest explanation, would be an aerodynamic structural breakup of the shuttle caused by it rolling at the wrong angle. Remember, after reentry, the shuttle is descending without power, which means astronauts at the controls can't compensate for a loss of attitude by using the engines, they can only do so using the flaps. And that's extremely hard. Astronauts describe piloting the shuttle on reentry as like trying to fly a brick with wings. It's very difficult to operate, and even more so to correct any problems.

A second explanation might be a loss of tiles leading to a burn-through. (The shuttle is covered with heat-resistant tiles to protect the craft and those inside it from burning up in the scorching temperatures caused by the friction of reentry.) But I think that explanation is unlikely, because the tile-loss would have had to have been quite substantial for that to become possible. You'll hear a lot in the next few days about things falling off the shuttle during liftoff. But it often happens that they lose a few tiles, and I'd be surprised if it happened on a scale that could make an accident of this type possible.

The last option is some kind of engine failure leading to fuel ignition. Although the main tanks are mostly empty, there should still be fuel left in the maneuvering tanks. But probably not enough for an explosion that could have caused this breakup.

And just in case anybody was wondering, you can almost certainly rule out terrorism as a cause. This incident occurred well above the range of shoulder-fired missiles. And it would probably be easier to sneak a bomb onto Air Force One than to get one onto the shuttle.

NASA should get its act together. And maybe this will be a reminder that spaceflight is not yet 'routine", and that we should start putting more of our energies into serious space exploration instead of over-using technologies that in many cases where designed two decades ago.

Regardless of all that (which in any case is little more than tangential when loss of life is involved), a sad day for space exploration.

put up or shut up

Charles Cooper goes after the CEOs that just complain and offer few new solutions to the current "tech slump":

[The question stands] of whether CEO leadership in Silicon Valley, so lionized during the go-go days, is all that it's cracked up to be. Where's the imagination? Where's the outside-of-the-box thinking? Unfortunately, ordering yet another wave of mass layoffs doesn't qualify as evidence of managerial genius.