X-59: NASA’s effort to build a ‘quiet’ supersonic plane

(CNN) — If you’ve heard Sonic Boom recently, you probably remember it. A loud, explosion-like blast from an aircraft flying at the speed of sound — can be shocking and even shatter windows.

Now, NASA is working to change those rules, paving the way for a new generation of quiet supersonic aircraft. The agency is doing this through a program called Quest — for “Quiet SuperSonic Technology” — which is the result of decades of research and centered around a new aircraft called the X-59.

Distant thunder

“It’s going to be quieter than the Concorde or any of the supersonic jets out there today,” said Craig Nicol, project manager for NASA’s Quest program. “It’s very long and thin. It’s about 100 feet (30.5 meters) long, but it only has a wingspan of about 29 feet. The nose is a distinguishing feature on this plane: it’s about a third of its length.”

The sleek design plays a key role in keeping the aircraft quiet during overhead flight.

How the X-59 looks in flight.

cr103.com/NASA

But how does a sonic boom happen? When an airplane travels at subsonic speeds, the sound waves it normally creates can travel in all directions. At supersonic speeds, however, the aircraft leaves its own sound behind and the sound waves compress and merge into a single shock wave, starting from the nose and ending at the tail.

When this highly compressed shock wave hits the human ear, it produces a loud sound that does not occur when the plane breaks the sound barrier, but is a continuous impact that can be felt by anyone in the cone-shaped area under the plane. As long as it exceeds the speed of sound.

The shape of the X-59 is designed to prevent shock waves from clumping together. Instead, they are deployed with the help of strategically placed airfoils. The only engine is at the top rather than the bottom of the plane to maintain a smooth low profile that prevents shock waves from reaching the ground.

As a result, NASA believes the X-59 will produce only 75 decibels of noise at high speed, compared to Concorde’s 105 decibels.

“What this means is, this plane can look like distant thunder on the horizon or someone slamming the car door,” says Nicole. “In fact, people may not hear the noise at all, and if they do, they certainly won’t be alarmed, because it’s low and flat, and it never screams.”

Changing the rules

A critical part of the program will begin in 2024, with a series of more than half a dozen test flights across the U.S. selected to provide a diverse mix of geographic and atmospheric conditions. of the project, because we’re working with the public to create a little bit of citizen science,” says Nicole.

After X-59 flies over selected locations, NASA will contact communities on the ground to assess their response to the rumble. The goal is to prove the theory that the 75-decibel boom will be accepted.

The data collected in this way will be used to monitor aircraft noise regulation for the International Civil Aviation Organization (ICAO) to persuade it to improve it at an international meeting scheduled for 2028.

First flight is planned before the end of the year.

Darren Russell/NASA

A new generation

NASA believes the rule change will open up the skies for a new generation of superplanes, allowing them to fly on currently unapproved routes such as New York to Los Angeles, and cut flight times in half.

However, we do not know what those planes will look like and who will make them; Because the X-59 is a technology demonstration, not a prototype.

Nicol features an extended nose, some flight control systems, and the X-59’s unique external vision system, which provides the pilot with high-resolution displays of what’s ahead in the absence of a forward-looking window due to the aircraft’s streamlined nose.

Nicol believes that such planes will democratize supersonic travel with the ability to fly anywhere, which is a distinct contrast to Concorde’s luxury: “If you look back 100 years, a lot of advanced mobility technologies came into play, including railroads and airplanes. As a premium experience, something But as technology advanced and costs fell, they became accessible to the general public.

“One of the long-term goals is to offer this high-speed travel as a broad application, and there’s no reason why that shouldn’t happen.”