The Northrop Grumman X-47B is a demonstration unmanned combat aerial vehicle (UCAV) designed for aircraft carrier-based operations. Developed by the American defense technology company Northrop Grumman, the X-47 project began under the Defense Advanced Research Project Agency (DARPA) as part of the Joint Unmanned Combat Air Systems (J-UCAS) program, and subsequently became part of the United States Navy's Unmanned Combat Air System Demonstration (UCAS-D) program. The X-47B is a tailless jet-powered blended-wing-body aircraft capable of semi-autonomous operation and aerial refueling.