Virgin Galactic has released the final design of the launch system that will take fare-paying passengers into space.
It is based on the X-Prize-winning SpaceShipOne concept - a rocket ship that is lifted initially by a carrier plane before blasting skywards.
The Virgin system is essentially a refinement, but has been increased in size to take eight people at a time on a sub-orbital trip, starting in 2010.
Virgin boss Sir Richard Branson said the space business had huge potential.
"I think it's very important that we make a genuine commercial success of this project," he told a news conference in New York.
"If we do, I believe we'll unlock a wall of private sector money into both space launch systems and space technology.
View: BBC News