NASA's X-59 reaches supersonic speed in milestone flight

NASA's experimental X-59 plane has achieved supersonic flight for the first time, reaching a peak speed of 713 miles per hour at an altitude of 43,400 feet on June 5, 2026. The 81-minute flight, piloted by NASA pilot Jim Less from Edwards Air Force Base, marked a major milestone in the agency's decades-long effort to develop commercial supersonic travel that does not produce disruptive sonic booms. The aircraft, developed by Lockheed Martin under a $247.5 million contract awarded in 2016, completed its first flight in October 2025 and has since conducted more than a dozen test flights. The X-59, part of NASA's Quesst (Quiet SuperSonic Technology) mission, features an unusually long nose designed to disperse shock waves so that flight produces what NASA describes as a "quiet supersonic thump" rather than the thunderous boom associated with high-speed aircraft. When conventional aircraft break the sound barrier, pressure waves funnel to the rear and create a sonic boom that can exceed 110 decibels, which is why supersonic flights have been banned over populated areas since the retirement of the Concorde in 2003. The X-59's design aims to replace that explosive sound with something more akin to distant thunder or a car door closing 20 feet away. The test flight program will continue with planned speeds reaching Mach 1.6, equivalent to 1,218 miles per hour, and altitudes of 60,000 feet. Once testing is complete, NASA will conduct a second phase focused specifically on measuring the noise the plane produces, followed by a final phase that will relocate tests over communities where NASA will survey residents on their impressions of the aircraft's sound. Scientists hope the successful development of the X-59 will eventually pave the way for the revival of commercial supersonic passenger flights, which once seemed destined to disappear after the Concorde's retirement.