I'm not sure about that. At its launch speed (lower limit 66 km/s) it would have taken under a second to get to where the atmosphere is no longer thick enough.. would that have been enough time to vaporize it?

It's the other way around. Regardless of speed, it has the same number of particles to displace. At high speed these particles you're hitting are like hitting a concrete wall. The faster you go, the worse it is, and the less time you have to cool down the heat you're generating.