Boeing space plane returning from year-long secret mission
X-37B Orbital Test Vehicle
Credit: US Air Force
Technicians in self-contained atmospheric protective ensemble suits start to conduct initial checks on the X-37B Orbital Test Vehicle 1) after its landing Dec. 3, 2010, at Vandenberg Air Force Base, Calif. This is the Air Force's first unmanned re-entry spacecraft. (U.S. Air Force photo/Michael Stonecypher)
