The X-37B Orbital Test Vehicle is an unmanned space test vehicle for the USAF. The X-37B is based on NASA's original X-37 design, the secretive plane's launch test flight was in April 2010. A second test flight, using a second vehicle - the Orbital Test Vehicle 2 - launched in March 2011. Take a look at the basic facts of the X-37B robotic space plane in the SPACE.com infographic above.
(Image: © Karl Tate, SPACE.com)