NASA’s latest experimental aircraft, designed to achieve supersonic flight without triggering a sonic boom, will be called the X-59 QueSST. Currently under construction by Lockheed Martin, the X-59 is designed so that when the aircraft is flying at supersonic speeds, people on the ground will hear nothing more than a soft thump—if they hear anything at all.
The proposed aircraft will be 94 feet long with a wingspan of 29.5 feet. According to research, the expected speed of the X-59 at a cruising altitude of 55,000 feet is Mach 1.42, or 940mph. Its top speed will be Mach 1.5, or 990mph. The jet will be propelled by the same engine that drives F-18 fighter jets. A single pilot will be in the aircraft’s cockpit.
The explanation behind how the X-59 makes a quiet sonic boom is in the way its uniquely shaped hull design generates supersonic shockwaves. Shockwaves from a conventional aircraft design merge as they expand away from the airplane’s nose and tail, resulting in two distinct and thunderous sonic booms.
In contrast, the X-59’s shape sends those shockwaves away from the aircraft in a way that prevents them from coming together to create those loud booms. Instead, the much weaker shockwaves reach the ground still separated. These waves would be heard as, at most, a quick series of soft thumps that would be comparable to the sound of a car door closing.
Current regulations ban supersonic flight over land—thanks in part to the loud sonic booms created by the Concorde, which was forced to restrict its activities to transatlantic flights because of the sounds the aircraft made when it reached supersonic speeds.
Once fully tested and pronounced safe to fly within U.S. airspace, the X-59 will begin making supersonic flights in late 2022 over select communities to measure residents’ reactions to any sound they might hear that the aircraft produces.
The data gathered from these community overflights will be presented to U.S. and international regulators, who will use the information to help them propose rules based on noise levels that could enable supersonic flight over land.
“I’m confident that the contributions the X-59 QueSST will make to our nation and the world will ensure its place among the greatest NASA X-planes ever flown,” said Jaiwon Shin, NASA’s associate administrator for aeronautics.
NASA isn’t the only aerospace organization trying to solve the sonic boom problem. Spike Aviation is developing a commercial supersonic aircraft by 2023. And Boeing recently announced that it hopes to develop a hypersonic passenger jet that would fly from New York to London in two hours.
Find out more about the race to fly quietly at supersonic speeds at Spike Aviation to Produce Supersonic Passenger Jet by 2023.