The private space plane, called SpaceShipTwo, is set to begin carrying passengers to the edge of space on suborbital rides in 2014. Already, 600 people have signed up for flights, including actors Ashton Kutcher and Angelina Jolie, singers Justin Beiber and Katy Perry, and Virgin Galactic's celebrity founder himself, Sir Richard Branson.

SpaceShipTwo has 500 cubic feet (14 cubic meters) of interior space available for experiments, the most of any of the crewed suborbital vehicles now under development. The passenger cabin can fit the equivalent of 20 space shuttle mid-deck locker equivalents as well as a flight test engineer who will run experiments.