The X-59 QueSST aircraft is an experimental design that is part of Low-Boom Flight Demonstrator (LBFD) test, a cooperation between Lockheed Martin and NASA. It is a test to gather community response data on the sonic boom generated by the aircraft, helping NASA establish an acceptable commercial supersonic noise standard to overturn current regulations banning supersonic travel over land. This would open the door to an entirely new global market for aircraft manufacturers, enabling passengers to travel anywhere in the world in half the time it takes today as the mighty Concorde once did. (2)
The X-59 is designed to cruise at 55,000 feet at a speeds of 940 mph and create a soft “thump” like that of a car door closing (75 Perceived Level decibel (PLdB), instead of a sonic boom. Unlike the Concorde, this will create less noise disturbance around the community, preventing breakage of windows and cars’ alarms going bonkers. (2)
But what are theses sonic booms you say? Well, let’s get to the basics first. When an object moves through the air, it creates pressure waves in front and behind it. As the object moves faster, the pressure waves build up and are compressed together and they will eventually form a single shockwave at the speed of sound. The sonic boom one hears caused by an airplane flying at Mach 1 usually takes the form of a “double boom”. The first is caused by the change in air pressure as the nose of the airplane reaches Mach 1, and the second is caused by the change in air pressure that occurs when the tail of the plane passes and air pressure returns to normal. If a plane travels at Mach 1 or faster, it will generate a continuous sonic boom. Those directly below the aircraft will hear the sonic booms. This path is called the “boom carpet”. (3)
With these concepts in mind, the X-59 is designed to makes these shockwaves less disruptive to the community. It follows the Concorde design with its sleek nose and slim design. However, the X-59 is only a test and requires further experimentation before flying through domestic air. (1)
The program is divided into three phases:
2019 – NASA conducts a critical design review of the low-boom X-plane configuration, which, if successful, allows final construction and assembly to be completed.
2021 – Construction of the aircraft at Lockheed Martin’s Skunk Works facility in Palmdale is completed, to be followed by a series of test flights to demonstrate the aircraft is safe to fly and meets all of NASA’s performance requirements. The aircraft is then officially delivered to NASA, completing Phase One.
2022 – Phase Two will see NASA fly the X-plane in the supersonic test range over Edwards to prove the quiet supersonic technology works as designed, its performance is robust, and it is safe for operations in the National Airspace System.
2023 to 2025 – Phase Three begins with the first community response test flights, which will be staged from Armstrong. Further community response activity will take place in four to six cities around the U.S. (4)
A jet flying at Mach 1 and breaking the sound barrier
An illustration of the X-59 aircraft
(1) Brown, Katherine. “NASA Completes Milestone Toward Quieter Supersonic X-Plane.” NASA, NASA, 26 June 2017, http://www.nasa.gov/press-release/nasa-completes-milestone-toward-quieter-supersonic-x-plane.
(2) “X-59 QueSST.” Lockheed Martin, http://www.lockheedmartin.com/en-us/products/quesst.html.
(3) “What Is a Sonic Boom?” Wonderopolis, wonderopolis.org/wonder/what-is-a-sonic-boom.
(4)Gipson, Lillian. “New NASA X-Plane Construction Begins Now.” NASA, NASA, 2 Apr. 2018, http://www.nasa.gov/lowboom/new-nasa-x-plane-construction-begins-now.