Here’s my thoughts on the SpaceX launch failure, written while the debris is still smoking in the water. This is what I saw, replaying the YouTube video.
At first I thought it was a staging failure. You often get that cloud burst as the main engines cut off (and the remaining fuel in the pipes evaporates), the explosive bolts separate the two stages, and the second stage engines flare fuel clouds before igniting. But this happened approximately 44sec after MaxQ, the point when the atmospheric forces on the vehicle are highest (before this, it’s not moving fast enough; after this, the atmosphere is getting too thin), and roughly 30sec before scheduled MECO (I’m taking these values off the timeline at the bottom of the vid).
At 23:44 into the video (not into the flight), there’s a puff of white gas from the right-hand side of the booster. This billows out into an explosion three seconds later, with the shadow/sillhouette of something that might be part of the rocket, or might be a cloud shadow (but probably isn’t, because of how long it lasts).
At 23:49, the cloud starts to clear, and we see what looks like a normal engine burn. This is visible for another three seconds, when everything is overwhelmed with cloud, with no signs of flame, which clears two seconds later, to show multiple debris fragments.
UPDATE: Elon Musk has tweeted that it looks like there was an overpressure event in the second stage liquid oxygen tank. That would produce a white cloud when the tank blew out, followed by an explosion above the main body of the booster as the oxygen ignited. The first stage keeps firing, not realizing that it’s been chopped off at the hips.
Here’s the vid
Just a note on the language of reporting. A couple of news sites are calling this a failure of SpaceX’s efforts to recover a booster after launch. They seem to be confusing the up-goer and down-goer parts of the mission. The mission was a failure. The effort to put a resupply capsule into orbit was a failure. Landing the booster on a ship was never tried.
Second note. Musk’s tweet was posted an hour and a half after the event. Pretty fast reporting, and an amazing display of openness.
Conclusion. Space is hard. You fail a lot. You learn from each failure, and you want your failures early, before whatever caused them is baked in. It’s like that old video game. You may die; your little dog may die, but eventually, Oregon gets settled.
To quote Julia Ecklare, the only way to go from here is out.