Science | X-37B Spy Plane Ending Its 2 Secretive Years in Space Air Force's X-37B to complete 3rd secret mission today By Rob Quinn Posted Oct 14, 2014 2:13 AM CDT Updated Oct 14, 2014 6:03 AM CDT Copied This March 30, 2010, photo shows the X-37B Orbital Test Vehicle during testing at the Astrotech facility in Titusville, Fla. (AP Photo/US Air Force via NASA) Some 673 days after it was launched into space for a secret mission, the Air Force's robotic X-37B space plane is set to return to Earth today—and there's still no word on what it was doing up there. Some rumors say that the robotic mini-space shuttle was interfering with foreign satellites or functioning as a space-based bomber. Sources tell the Daily Beast that the spacecraft is designed to carry specialized payloads of sensors like ground-mapping radars—useful stuff for the military to have on a spacecraft with an orbit over countries including Iran, Afghanistan, and China. This is the third space mission for the Boeing-built craft, which is overseen by the US Air Force Rapid Capabilities Office. Space.com notes that while all the plane's landings so far have been at an Air Force base in California, Boeing is retooling an old NASA shuttle hangar for the X-37B. The X-37 program has "conducted testing at Kennedy's Shuttle Landing Facility to demonstrate that landing the vehicle at the former shuttle runway is a technically feasible option," NASA says in a statement. Read These Next White House rolls with Trump's 'daddy' nickname. New Fox star, 23, misses first day after car troubles. Supreme Court ruling is a big blow to Planned Parenthood. Gavin Newsom has filed a massive lawsuit against Fox News. Report an error