The U.S. military plans to land its secretive X-37B robotic space plane in California on Tuesday, ending a classified 22-month mission, officials said.
The exact time and date will depend on weather and technical factors, the Air Force said in a statement released on Friday. The X-37B space plane, also known as the Orbital Test Vehicle, blasted off for its second mission aboard an unmanned Atlas 5 rocket from Cape Canaveral Air Force Station in Florida on Dec. 11, 2012.
The 29-foot-long (9-meter) robotic spaceship, which resembles a miniature space shuttle, is an experimental vehicle that first flew in April 2010. It returned after eight months. A second vehicle blasted off in March 2011 and stayed in orbit for 15 months.
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