Richard Branson first vowed that one day he would make it into space when he was watching the Moon landings in 1969 with his family.

Now his dream of a commercial flight that crosses the final frontier is coming ever closer, with steady work on the prototypes of the spaceships that will take paying passengers into space.

So far around 450 passengers have signed up for the experience. They will go up in a six-passenger, two-pilot craft whose trajectory will overlap the Earth's atmosphere at 70,000ft, making it a suborbital flight with a short period of weightlessness.

The entire flight will take about three-and-a-half hours and the weightlessness will last six minutes, during which passengers will be able to release themselves from their seats and float around the cabin.

Many of those who have signed up attended the VIP unveiling of SpaceShipTwo at the Mojave Air and Spaceport, where California governor Arnold Schwarzenegger and New Mexico governor Bill Richardson christened the spaceliner Virgin SpaceShip (VSS) Enterprise.