This is a great link, thanks. I'm watching it and I have a question about reentry (should apply to all capsules, like Apollo, SpaceX not only MSL): basically, how is this thing stable?

I see the animation and how the capsule twists and turns, and I'm nervous, why doesn't the capsule destabilize and start to tumble? It's not spinning (like a bullet) so how come it stays heat shield down?

Perhaps some kind HN-er with aerodynamic knowledge can write a brief answer for the layman (I'm sure others here might have the same question).

Thanks