|February 23, 2013
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."The mission is ongoing," Air Force Maj. Eric Badger, a spokesman for the X-37B program, told SPACE.com. "As with previous missions, the actual duration will depend on test objectives, on-orbit vehicle performance and conditions at the landing facility." [Photos: U.S. Military's X-37B Space Plane]