Here's What We Know About The Air Force's Mystery Mission

The U.S. Air Force is set to launch the fourth flight of its X-37B space plane on May 20, and new details are unfolding about the upcoming mystery mission.
For this latest flight of the X-37B space plane, also known as the Orbital Test Vehicle, the Air Force Rapid Capabilities Office has teamed up with several partners, including NASA, to test experimental space technologies. Randy Walden, director of the Air Force Rapid Capabilities Office overseeing the flight, said in a statement, "With the demonstrated success of the first three missions, we're able to shift our focus from initial checkouts of the vehicle to testing of experimental payloads."