NASA's Marshall Space Flight Center image shows on-orbit functions for the reusable X-37 space plane, now under the wing of the U.S. Air Force.
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.
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