Inside NASA’s X-59 Low-Boom Demonstrator

“We never changed the requirements after the first four or five design iterations—the airplane looked basically the same,” Coen says. “It was just a matter of figuring out how to do an X-plane again.” Following a preliminary design review in June 2017, a contract to build the aircraft was awarded to Lockheed Martin in April 2018, marking the start of the detailed design phase. The finalized external configuration, dubbed C612, was settled about the time of the critical design review in September 2019.

The aircraft is specifically shaped to produce a sine-wave-shaped sonic boom measuring 75 PLdB (perceived level decibels), a sound roughly comparable to a car door slamming around 20 ft. away. This contrasts with the 105 PLdB sound—equivalent to being inside the car when the door slams—made by the Concorde’s N-wave “double-bang.”