Schlieren image taken of a small scale model of the X-59 aircraft during wind tunnel testing at NASA's Glenn Research Center, Cleveland, Ohio, USA. The X-59 is being designed to produce sonic booms that are so quiet they will only be heard from the ground as sonic thumps or not at all. NASA and Lockheed Martin are conducting this research as part of the Commercial Supersonic Technology project. This project aims to remove the technical barriers for commercial supersonic flight.