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This Saturday, June 16, 2012 image from video made available by the Vandenberg Air Force Base shows an infrared view of the X-37B unmanned spacecraft landing at Vandenberg Air Force Base. The spacecraft, which was launched from Cape Canaveral Air Force Station in Florida in March 2011, conducted in-orbit experiments during the 15-month clandestine mission, officials said. It was the second such autonomous landing at the base. (AP Photo/Vandenberg Air Force Base)

Air Force's mystery mini-shuttle

A top-secret mini-space shuttle has blasted off from Cape Canaveral. The Air Force launched the unmanned spacecraft Dec. 11 aboard an Atlas V rocket.