In article , says...
SpaceShip 1 is an impressive project. Make no mistake about that.
But it's a very limited system, for a very limited purpose. While I'd
be more than happy to bet that they'll win the X-Prize, it's not going
to advance the State of the Art.

hmm... If "state of the art" includes concepts like "cost
effectiveness" then SS1 does advance the SOTA.
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins