Apparently simply having landing legs on the stage (and extending them) will be enough to stabilize the spin problem sufficiently to allow it to be controllable by the RCS et al.

Since you've been likely keeping up with this, has there been any video released on the fate of the return stage? Musk mentioned they would put something out there, but it doesn't seem to have materialized yet.

I realize that Elon speculated that would be the case, but I wasn't neccesarily buying his explanation.

Two things need additional color, one being given the lack of atomosphere at the altitude where the first stage separates (tapes put it at just over 3 minutes into the flight), and two structural integirty of those struts making the atmospheric transition.

So you need to get the retro burn off while you are exo-atmospheric or you risk melting off the important bits when you re-enter. That suggests that you need some sort of RCS to cut rotational dynamics so that you can stage for retro, then re-enter at less than hypersonic velocity. Further you can't do you retro burn until you've allowed the upper stage to clear.

Another interesting bit is that the first stage appears to have cameras, they were showing video from them during the launch, but we've not seen the post separation video. I hope that video surfaces at some point as it could help design something to mitigate the whole roll thing before it got out of hand.

Musk has mentioned posting that video online[1].

[1] http://www.reddit.com/r/spacex/comments/1ne36t/partial_succe...

great resource thanks. Looks like the first test with legs is going to be in FL.

I thought the spin problem was a non issue: they just wanted to see if they could relight the engine when Falcon is falling back to earth at speed. When it's relit they can compensate the spin and take control.

The challenge was that with the stage spinning they couldn't feed fuel to the engines to finish the retro burn. That is an issue. They need to work around that in the next attempt (either by not spinning or by allowing for it with a different fuel feed mechanism)

Increasing tank pressurization would mitigate it, but I suspect it's a lot easier to plan to control the spin.

It is a fascinating problem, you launch with one type of space craft and then you recover with a different craft (in terms of mass distribution, fuel supply, etc). I'd love to hear how the avionics deals with the two systems. especially given that most of the rocket systems I've seen internal descriptions of are very narrowly tuned to be critically damped around their launch parameters. Unlike say aircraft that are dealing with fuel weight management issues and load balancing.

I know Elon said he would release the videos, and I'm sure they will, this is definitly the kind of 'rocket science' that is very intriguing to me.