Watch NASA's new experimental jet break the sound barrier for the first time NASA's X-59 jet has broken the sound barrier for the first time, a major milestone in the effort to build a quiet supersonic aircraft for civilians. The sleek, needle-nosed airplane exceeded the speed of sound for the first time on Friday, June 5. NASA test pilot Jim "Clue" Less took off in the plane at 11:08 a.m. PT and landed at Edwards Air Force Base in California about 81 minutes later. At the aircraft's top speed, it went Mach 1.1 — about 713 mph — at an altitude of 43,400 feet. The X-59 is experimental, part of the so-called QUESST mission to transform passenger air travel over land. Because existing supersonic aircraft produce loud sonic booms at high speed, the U.S. government bans routine supersonic flights over populated areas. But the X-59, designed by NASA and its contractor Lockheed Martin, is expected to tame the boom into a mere thump. You May Also Like NASA captured the achievement from the vantage point of a chase plane, which kept pace with the speedy experimental jet to monitor the test. You can watch the historic moment when it clocked supersonic speed in the video below. "X-59 goes through the number!" NASA administrator Jared Isaacman said on X. "We are rebuilding our X-plane portfolio and getting NASA back in the business of radical airframe and engine flight test!" An X‑plane is a U.S. aircraft designed to test new flight technologies and ideas. The goal of the X-59 is to provide regulators and the airline industry with the evidence needed to reconsider restrictions on supersonic aircraft. Most people think of NASA as the gateway to space, but the organization is first and foremost the nation's civil aeronautics agency (quite literally, the