Virgin Galactic SpaceShip2 Test Flight

MOJAVE, CA - APRIL 29: (EXCLUSIVE COVERAGE) (EDITORIAL USE ONLY, NO SUBJECT SPECIFIC TV BROADCAST DOCUMENTARIES OR BOOK USE) Pilots, (L-R) Clint Nichols,Mike Alsbury,Brian Maisler, Mark Stuckey and Dave McKay of Virgin Galactic's WhiteKnight2 and SpaceShip2 walk towards the aircraft for the first rocket powered flight (PF01) since the beginning of the program that began in 2005 on April 29, 2013 in Mojave, California. SpaceShipTwo is a private enterprise aircraft, designed to carry paying passengers into space. The spacecraft was dropped from the mothership at high altitude and fired it's engine for a approximate 16-second burn taking the craft through the sound barrier. The hybrid rocket motor is fueled by nitrous oxide and a rubber propellent combination. The motor can be "shut down" at any time for safety and flight requirement purposes. (Photo by Jason DiVenere/Virgin Galactic/Getty Images)