US Air Force’s X-37B Space Plane Mystery Mission Wings by 500 Days in Orbit

supersecretxnews54s54f45fsx-37b-space-plane-orbit-image-artThe latest secretive mission of the United States Air Force’s X-37B space plane has cruised beyond 500 days in Earth orbit since its launch last year.
The U.S. military launched the robotic X-37B space plane on May 20, 2015, marking the fourth flight for the Air Force program. A United Launch Alliance Atlas V rocket lofted the spacecraft from Florida’s Cape Canaveral Air Force Station to kick off the OTV-4 mission (short for Orbital Test Vehicle-4).