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FILE - This undated file image provided by the U.S. Air Force shows the X-37B spacecraft. The unmanned Air Force space plane steered itself to a landing early Saturday, June 16, 2012, at a California military base, capping a 15-month clandestine mission. (AP Photo/U.S. Air Force, File)

Mystery Mini Space Shuttle X-37B Lands in California

The Air Force's X-37B, is an unmanned reusable spacecraft built by Boeing that has spent more than a year on a classified mission in space. It landed early Saturday, June 16, morning at Vandenberg Air Force Base in California after weather conditions kept pushing back landing attempts the last few days.