Richard Lamb wrote:

That seems like a reasonable question.
Wish I knew a reasonable answer.

For one, the shuttle comes in from much
higher and has no way to slow down _before_
reentering. The speed and angle are pretty much
fixed, so all you can do is find a way to dissipate
the heat that *will* build up. The tiles and other
thermal protection on the shuttle are (compared to
SS1) big and bulky. I suppose they could put more
TPS on SS1, but it would most likely change the
shape, pretty much requiring a new design.
There is no doubt in my mind that if Scaled
decides to go orbital, they will succeed (eventually),
and the design will be, er, revolutionary.

Dave 'ablative' Hyde