NASA's quiet X-59 supersonic jet finally breaks sound barrier

This is a story that has been languishing in the background for quite some time. NASA has been working to reduce the amount "sonic boom" that aircraft make as they exceed the speed of sound for several years, and rolled out the first prototype of an experimental supersonic airplane called X-59 in August of 2023. The X-59 bears little to no resemblance to current supersonic fighters like the F35 or earlier craft like the F-22 or F-18. That said, they've been modeling and talking openly about it for much longer than just since 2023.  

Today, the X-59 actually flew faster than the speed of sound for the first time. 

Friday's flight began and ended at Edwards Air Force Base in California. The X-59, with NASA test pilot Jim "Clue" Less at the yoke, took off at 2:08 p.m. EDT (1808 GMT; 11:08 a.m. local California time) and touched down 81 minutes later.

Less took the jet to a maximum altitude of 43,400 feet (13,228 meters) and a top speed of 713 mph (1,147 kph). That works out to about Mach 1.1, or 1.1 times faster than the speed of sound, NASA officials said in the statement. (The speed of sound varies with temperature, as sound waves move faster in warmer air. At sea level, where the air is relatively warm, Mach 1 is about 761 mph, or 1,225 kph.)

NASA’s X-59 quiet supersonic research aircraft exceeded the speed of sound for the first time on June 5, 2026. (Image credit: NASA/Lori Losey)

Don't expect the X-59 crew to rest on their laurels - they're planning on a bigger follow-on mission soon. 

In just a few days, they plan to send the plane on its first "mission conditions" flight — one that reaches a top speed of Mach 1.4 and an altitude of about 55,000 feet (16,764 m).

"This speed and altitude are the base conditions for the X-59 when it will eventually fly over several U.S. communities, enabling NASA to gather data about how people may perceive its quiet thump," NASA officials wrote in the same statement. 

"NASA will share this data with U.S. and international regulators to help establish new data-driven noise standards to enable a future viable market for supersonic commercial flight over land," they added.

The X-59 was built by the Lockheed Martin Skunk Works - a group that has quite a range of "first ever" air craft and their flights.

"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," NASA Administrator Jared Isaacman said in the same statement. "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."