That was an unmanned one, n'est-ce pas?
As previously stated, devices like this have been around for a while, the unmanned ones get up to some ludicrous speeds , usually for testing some kind of technology (or seeing what happens when it slams into a huge block of concrete)
The manned ones, that test things like ejection seats don't go quite so fast, but if we were to do some sort of speed record attempt, we'd need a brain-damaged guinea pig, or something, to drive it..