British billionaire Richard Branson, left, and the aerospace designer Burt Rutan unveil a model of SpaceShipTwo, right, the vehicle they hope will be able to take passengers on suborbital joy-rides, just for the fun of it, with test flights beginning as soon as this year, during a news conference in New York, Wednesday, Jan. 23, 2008. At top is a model of White Knight Two, the mothership for Space Ship Two, which is now under construction at a hangar in the Mojave Desert. [Agencies]