NASA’s X-59 experimental aircraft reached a major milestone Friday, June 5, when it flew faster than the speed of sound for the first time.  

The 81-minute flight achieved a speed of Mach 1.1 (approximately 713 mph) at an altitude of 43,400 feet, with the X-59 performing as expected. For NASA test pilot Jim “Clue” Less, the plane’s instruments were the only indication of flying supersonic — exactly what the team wanted. 

“You know you are supersonic when gauges say you are supersonic. I didn’t feel anything,” Less said. “It went smoothly, and we easily got to Mach 1.1.” 

The X-59 is designed to fly at supersonic speeds while creating only a quiet thump instead of a loud sonic boom. For this flight, a NASA F‑15 chase plane flew nearby to monitor the test. Its loud sonic booms obscured any sound made by the X-59. The X-59 will conduct flights focused on its sound profile during a later phase of testing. 

Now that the X-59 has officially kicked off supersonic flight tests, the next big step is its first mission conditions flight. During this test, the X-59 will fly at the same speed and altitude planned for future tests, where the aircraft will fly over several U.S. communities to gather data from people on the ground about its noise levels: Mach 1.4 (925 mph) at 55,000 feet.  

“The plane wants to go faster, and we are looking forward to that,” Less said. 

The X-59 is the centerpiece of NASA’s Quesst mission, which aims to demonstrate quieter supersonic flight and to help enable commercial supersonic flight over land.  

This flight was also the first time the X‑59 appeared in NASA’s flight tracker.

More X-59 to Explore

Read more on the Quesst mission page.