The military is poised to launch an unmanned winged spacecraft resembling a miniature space shuttle Thursday and it probably won't be a one-time shot. Gary Payton, Air Force deputy under secretary for space programs, said Tuesday the Air Force has contracted for a second space plane depending on the success of the prototype's maiden flight. After a decade of development, the X-37B Orbital Test Vehicle is slated to launch from Florida and spend up to nine months in orbit. It will re-enter Earth on autopilot and land like an airplane at the Vandenberg Air Force Base, California. The spacecraft will conduct classified experiments while in orbit. Payton said the Air Force's main interest is to test the craft's automated flight control system and learn about the cost of turning it around for launch again. Built by Boeing's Phantom Works division, the X-37 program was originally headed by NASA. It was later turned over to the Pentagon's research and development arm and then to a secretive Air Force unit.