The U.S. Air Force is set to launch its so-called secret X-37 Orbital Test Vehicle space plane from Cape Canaveral, Fla. Tuesday for the third test flight of the prototype space craft. The Air Force’s third Orbital Test Vehicle (OTV-3) mission is scheduled for lift off from Launch Complex 41 at Cape Canaveral Air Force Station at 1:03 p.m. ET, with the launch window extending through 6:03 p.m. As with the OTV-1 and OTV-2 missions, the third flight of the X-37B will begin atop an Atlas V rocket supplied by the ULA, a joint venture by Boeing and Lockheed Martin.
The Boeing X-37 is a reusable unmanned spacecraft designed to be boosted into space using a rocket and then re-entering Earth’s atmosphere to land as a spaceplane. The X-37 began as a NASA project in 1999, before being transferred to the U.S. Department of Defense in 2004. It conducted its first flight as a drop test on 7 April 2006, at Edwards Air Force Base, California. The spaceplane’s first orbital mission, USA-212, was launched on 22 April 2010 using an Atlas V rocket. Its successful return to Earth on 3 December 2010 was the first test of the vehicle’s heat shield and hypersonic aerodynamic handling. A second X-37 was launched on 5 March 2011, with the mission designation USA-226; it returned to Earth on 16 June 2012.