Secret Space Plane, U.S. Air Force's Robotic X-37B, Continues Mysterious Mission

Secret Space Plane, U.S. Air Force's Robotic X-37B, Continues Mysterious Mission: "The U.S. Air Force's mysterious X-37B space plane is quietly chalking up mileage in space more than two months after its latest launch into orbit.



The robotic X-37B space plane soared into orbit atop an Atlas 5 rocket from Florida's Cape Canaveral Air Force Station on Dec. 11. The mini-shuttle's mission is known as Orbital Test Vehicle-3 (OTV-3), since it is the third classified mission under the Air Force's X-37B program.

How long OTV-3 will remain in Earth orbit is unknown. The hush-hush space plane mission is officially on Air Force space tracking books as USA-240."