re: re: Assessment of the X-Prize contestants
Rutan's rocket is "air launched" - the rocket part does not take off on its own from the ground.
From my reading of the article, this saves you the wing and wheel weight needed to support the fully loaded rocket, which you would need for a true horizontal take off rocket. However, the rocket needs to be able to dump all the propellant in the case of an abort, to make a safe landing.
I think I read that Rutan's scheme is to have the carrying aircraft pitch up at a steep angle before separating the rocket, which would reduce the "steering losses" described in the article a bit.