[Moonman62]

With the tail raised at 100 knots, the airplane flies nearly ballistic. What about when it returns from 100 kilometers? Will it be so controllable at a much higher speed?

I believe the speed at altitude will still be relatively slow. Remember, they are going into space, not orbit.

[RightWhale]

the speed at altitude will still be relatively slow

It's going to hit the atmosphere at 3000 mph. That would strip the chrome right off the front bumper of my Chevy.