The US Successfully Launches Unmanned Drone For Secretive Space Mission. The US Air Force has successfully launched the mysterious X-37B space plane on a sixth secretive mission. The unmanned space drone can cruise for extremely long periods in low-Earth orbit without apparent need to refuel, and in an orbital pattern which makes it remarkably challenging to track. The drone will spend months in orbit, remotely handling a series of operations. The space plane X-37B is 29 feet long (nine meters), with a wingspan of 15 feet (4.5 meters). The drone, in turn, will use a small research satellite dubbed FalconSat-8, to carry out further investigations.