NASA’s Supersonic X-59 QueSST Is Coming
We are surrounded by a sound every day, from dogs barking, people talking and to highways, industry, and planes noise pollution. As a leader in aeronautics research, NASA is working to reduce some of these unwanted noises, the sounds produced by aircraft, to be exact. Well, in the days of the development of the first flying taxi in the world , we are rarely surprised. However, NASA comes really close to achieving that goal.
Lockheed Martin Aeronautics Company is building the X-59 QueSST aircraft at its famed Skunk Works facility in Palmdale, California. It is not a prototype for a commercial airliner. It is a one-of-a-kind experimental airplane equipped with quiet supersonic technologies that aircraft manufacturers may choose to include in their future designs.
The Low-Boom Flight Demonstration, a NASA aeronautics mission, includes the design, building, and testing of the X-59 Quiet Supersonic Technology Aircraft , or X-59 QueSST for short. The X-59 will be able to fly at supersonic speeds, faster than the speed of sound, without producing a loud sonic boom. Flying overhead, this aircraft will produce a soft “thump” sound in place of the sonic boom.
Why Do We Hear Such a Noise from a Plane?
To answer that question and understand what the sonic boom is, imagine an aircraft flying through the air. As it moves, the plane pushes air out of its way, continuously creating sound waves. At the speed of sound, the last ones move away from the aircraft in all directions. By increasing the aircraft’s speed to supersonic, the air pressure waves (they are similar to waves that pile up in front of a boat as it moves through the water) begin to pile up ahead of the airplane and compress.
In the air, the shock waves move out and away from the plane. That creates a sudden change in pressure. But it happens so quickly that when the energy from the shock wave reaches our ears, it is heard as a loud crack.
A New Era of Supersonic Aircrafts
So, how is NASA trying to quiet the sonic boom with X-59? Traditionally, airplanes that fly supersonically (such as Concorde or military jets) develop a loud sonic boom as they fly over the ground. Unlike a normal airplane, X-59 is very long and slender. The reason for that is to be able to shape the volume and the lift distribution over aircraft in such a way that shocks do not all coalesce into the strong front and rear ones.
The single-pilot craft has a wingspan of 29.5 feet and 94-feet long. The aircraft’s holes are designed to reduce the noise from shockwaves traditionally associated with max speed travel. The Space Agency says the X-59 is designed to separate the shockwaves resulting in much less noise reaching the ground.
The aircraft’s different shape alters how supersonic shock waves behave. Instead of coming together to be heard on the ground as a loud “boom-boom”, the shock waves do not merge and rapidly weaken. The sound heard on the ground is more like a soft “thump”, if it is heard at all.
How will the X-59 be used? NASA will utilize the aircraft to collect data on how effective the low-boom technology is in terms of public acceptance. This will be done by flying over select U.S. cities beginning 2020 and collecting, verifying, and validating data about community responses to the low-boom flights. The aircraft’s first flight test is scheduled for 2020.
What Are the Benefits for People on the Ground?
Commercial supersonic flight has long been desired to reduce air travel time and improve personal mobility. However, these benefits have not been realized due to the challenge of a sonic boom. When the Concorde was designed in the 1960s, the sonic boom was so disruptive to people on the ground that a prohibition was soon placed on a commercial supersonic flight over land that remains in effect today. This prohibition created an economic barrier that extinguished civil supersonic aviation. Sonic boom reduction has been pursued for many years, but NASA and its partners have made a number of significant advances that bring the goal much closer.
As of the end of December 2019, NASA’s X-59 QueSST is cleared for the final assembly. Three major areas of work are actively set up: the construction of the aircraft’s fuselage, wing, and empennage. The final assembly, including a 4K cockpit eXternal Visibility System , is scheduled for the middle of 2020. Are you ready to start a new decade of silent aircraft and flying cars?