Story ID: 
NASA’s X-59 Demonstrator Goes Supersonic
By: Kerry Lynch
Caption: X-plane reached Mach 1.1 during 81-minute flight
Word Count: 286
NASA’s X-59 experimental aircraft reached supersonic speeds for the first time on Friday, the agency announced. Piloted by NASA test pilot Jim “Clue” Less, the aircraft departed at 11:08 a.m. PDT from Edwards Air Force Base in California for an 81-minute flight that reached about Mach 1.1 and an altitude of 43,400 feet. 
During the June 5 flight, the X-59 team focused on flying qualities of the aircraft during subsonic and supersonic speeds. Plans call to stretch performance to Mach 1.4 and 55,000 feet in the coming days.
“X-59 is getting ready for its quiet supersonic debut. Since the aircraft’s first flight on Oct. 28, 2025, the team has made tremendous progress, flying 16 times in the last 90 days and getting into a steady test rhythm,” said NASA Administrator Jared Isaacman. “I’m grateful to the NASA team and Lockheed Martin Skunk Works for their help getting us to this point, and I hope this is the first of many collaborations as we rebuild NASA’s X-plane portfolio.”
The flight is part of a series of envelope expansion trials ongoing for the demonstration airplane, which was developed in concert with Lockheed Martin and will ultimately be used as part of the Quesst program that will explore the public impact of noise from the latest supersonic technologies. Data accumulated from that program will be used to evaluate whether supersonic flight over land will be feasible in the future.
According to NASA, the X-59 is designed to fly beyond Mach 1 while creating a “quiet thump” instead of a loud sonic boom. However, the June 5 flight also involved a NASA F-15 chase aircraft, which emitted sonic booms and obscured any sound of the X-59.