I think that the 1st stage separates at ~6000kmh; that's nowhere near the speed of orbit - which is around 28000kmh. I think that explains the ability of the f

I think that the 1st stage separates at ~6000kmh; that's nowhere near the speed of orbit - which is around 28000kmh. I think that explains the ability of the first stage to pass through the atmosphere without a heat shield - it's not the high up, more the speed, I think. From (again, not definitive) knowledge, the rocket fires to slow down (boostback), a re-entry burn, then a landing burn. Indeed, there's info from the horse's mouth here: http://www.spacex.com/news/2015/06/24/why-and-how-landing-rockets http://www.spacex.com/news/2015/06/24/why-and-how-landing-ro...