There is no question that Burt Rutan is a natural genius at aircraft design. His true innovation on SpaceShipOne was the shuttlecock styled effortless reentry system, and in particular, the ease of replacing these two large booms after a few flights to mitigate wear. SpaceShipOne/Two is a glider, and just like the Space Shuttle the wings are "only" used on the way down. There are wings used on the way up, of course, they are on WhiteKnightOne/Two, but once separated from the carrier aircraft the only lift is generated from the rocket.
As smart as Burt Rutan is, he's not a rocket guy. For SpaceShipOne he turned to Tim Pickens, a gifted rocket experimenter who became Scaled Composites' Propulsion Lead Engineer in 2002. It didn't last long, he was only there for a year, but in that time he gave them a motor. Think about that for a minute - it's truly remarkable. Because of that incredible pace the motor design was as simple as possible but no simpler, as they say. Being a hybrid, it shakes like a solid, along with half the reusability of a liquid.. and for some reason it can't restart and had half the performance of both. But it did the job.
Even before winning the prize, Scaled Composites signed a deal with Richard Branson to supply Virgin Galactic with a design for a new set of vehicles and form The Spaceship Company to put them into production. I'm not sure anyone thought it would take as long as it has, but Rutan set to work and delivered the scaled up vehicle designs with the creative names of WhiteKnightTwo and SpaceShipTwo.
Unfortunately, those designs also included details for RocketMotorTwo, which Scaled Composites decided to do in-house this time. Three years passed. In 2007 there was an accident which killed three and injured three more. Although the investigation cleared the company of any wrong doing, it was apparent that they were in a hole that they weren't climbing out of quickly enough.
In mid-2008 WhiteKnightTwo was unveiled. The media ate it up, but some of the statements made by Virgin Galactic's Will Whitehorn to promote the utility of the vehicle were a bit concerning. Everyone wanted to know: where's SpaceShipTwo? And the response seemed to be "we don't need it."
Late last year SpaceShipTwo was unveiled and Virgin Galactic had a big party. Since then, there has been captive carry tests and we're told there may be drop tests by the end of the year. It's all getting very exciting!
Oh I'm sorry, I was talking about the rocket wasn't I? I guess I got distracted by all the shiny white aircraft that I forgot all about it. Well, it seems Virgin Galactic have too.
Sometime between the 2007 accident and today Scaled Composites figured out that they're an aircraft company, not a rocket company, and decided to call in the Sierra Nevada Corporation to get back on track. Since then they've done hot fire tests which, of course, have been complete successes. Oh, they're using ablative nozzles too? Eww.
I've asked a lot of rocket professionals about these scraps of information and, in private, they've all told me the same thing. In public, "how would Jeff Greason say this?" is the what-would-Jesus-do of the space community, and this is how he said it:
In a sane world, a company that has a vehicle without an engine would purchase one from a company like XCOR, which specializes in engines.
So why can't Scaled Composites just buy the best rocket engines in the world (and yes, XCOR's engines really are that good). It would seem to be the rational decision. Apparently, the answer is simple: Rutan sold Branson a hybrid, so he has to deliver a hybrid. It doesn't matter how much hard won experience tells him that hybrids are not safer than liquids (or solids!). It doesn't matter that there's now acceptable engines that you can buy off-the-shelf that just weren't available 10 years ago when Rutan made his decision to go it alone. To change the deal now would loose face and more than likely have contractual implications.
And that's Scaled Composites' dirty little secret.