The hybrid Nitrous Oxide rocket that will take SpaceShipTwo to 65 miles above the Earth at 2500mph (YES!) has fired off for the first time in the southern California desert. Founder, adventurer and cool-guy-at-large Sir Richard Branson is happy:

As Virgin Galactic gets ever closer to the start of commercial operations, we are reaching and passing many important and historic milestones. The Virgin MotherShip (VMS) Eve, the first of our amazing, all carbon
composite, high altitude WhiteKnightTwo launch vehicles, is flying superbly. SpaceShipTwo, which will air launch from Eve, is largely constructed and awaiting the start of its own test flight programme later this year.

Rough translation from Brit:

OMFG THAT KICKED ASS! I CAN'T WAIT TO GET INTO THAT THING!

Yes, Sir Richard, I totally share the feeling. Even more because this time there have been no problems at all.

One of the cool things about the rocket is that is controllable and can be shut down safely at any time, allowing SpaceShipTwo to glide down to Earth at any time in case there's any problem. This is obviously one of the biggest concerns for the company: Safety.

The other big thing—other than putting amateur astronauts up there—is being green. They are trying to make the engine as clean as these things could be. The engine will burn for a very short period of time because it will be first lifted by White Knight II, which uses cleaner fuel. In fact, the carbon footprint for "each of its passengers and crew will be about a quarter of that for a return trip from London to New York."