Overview
- The X‑59 exceeded the speed of sound on Friday, June 5, 2026, reaching about Mach 1.1 (≈713 mph) near 43,400 feet during an 81‑minute flight from Edwards Air Force Base.
- A NASA F‑15 chase plane monitored the sortie but its own sonic booms obscured any acoustic measurement of the X‑59 on that flight, so dedicated sound tests remain necessary.
- The program will next conduct mission‑condition flights that aim to reach roughly Mach 1.4 at about 55,000 feet in the coming days to expand the aircraft’s flight envelope.
- The X‑59’s long tapered nose, engine placement and lack of forward windows paired with an eXternal Vision System are designed to break up shock waves so the ground hears a quiet ‘thump’ instead of a loud boom.
- Lockheed Martin built the jet for NASA under a roughly $247.5 million contract, and NASA plans community overflights and perception surveys to produce data for U.S. and international regulators and to inform future commercial supersonic service.