CNN  — 

NASA’s mission to revolutionize air travel has taken a significant step forward as the space agency starts building its X-59 QueSST supersonic jet.

The X-59 airplane is dubbed by some as “the son of Concorde” and is being manufactured, on behalf of NASA, by security and aerospace company Lockheed Martin.

NASA’s X-59 isn’t a prototype for a commercial airliner and can’t carry passengers – but its quiet, supersonic tech could be adopted by aircraft manufacturers in future designs.

“The start of manufacturing on the project marks a great leap forward for the X-59 and the future of quiet supersonic commercial travel,” said Peter Iosifidis, Low Boom Flight Demonstrator program manager Lockheed Martin Skunk Works in a statement.

NASA awarded Lockheed Martin a $247.5 million contract to build the highly anticipated aircraft.

Barely audible

Creating a supersonic aircraft that doesn’t produce sonic booms would be a game-changer for aviation. Before being taken out of service, Concorde’s speed was restricted over certain land routes because of disruptive sound waves.

If NASA’s experimental project works, it should help make supersonic flight more economical.

NASA completed tests in November 2018, using supersonic F/A-18 Hornet jets over Galveston, Texas, to mimic the sonic profile of the X-59 while a group of around 500 residents documented the noise levels.

By performing dives at the speed of sound, the jets produced two types of sonic boom in order to truly determine the sound they produce on the ground.

According to NASA, Galveston was chosen as the testing area as it’s located near the Gulf of Mexico, allowing the fighter jets keep louder sonic booms out to sea, while hurling quieter sonic “thumps” into the city.

Noise-reducing ability

F/A-18 Hornets will simulate regular sonic booms in Texas as part of the testing process.

The secret to the X-59’s noise-reducing ability is its uniquely shaped structure, designed so that supersonic shockwaves don’t build up into powerful sonic booms.

“With the X-59 you’re still going to have multiple shockwaves because of the wings on the aircraft that create lift and the volume of the plane,” says Ed Haering, an aerospace engineer at NASA’s Armstrong Flight Research Center. “But the airplane’s shape is carefully tailored such that those shockwaves do not combine.

“Instead of getting a loud boom-boom, you’re going to get at least two quiet thump-thump sounds, if you even hear them at all.

“This is why the F/A-18 is so important to us as a tool. While construction continues on the X-59, we can use that diving maneuver to generate quiet sonic thumps over a specific area.”

Concorde successor?

Formerly known as "Low-Flight Flight Demonstrator," the project has been renamed X-59 QueSST.

X-59 is designed to cruise at 55,000 feet at a speed of about 940 mph. It’s scheduled for delivery by the end of 2021. Once the aircraft has finally been constructed and its noise credentials established, NASA says it’ll carry out test flights over other US towns and gather intelligence from the ground.

“As we enter into the manufacturing phase, the aircraft structure begins to take shape, bringing us one step closer to enabling supersonic travel for passengers around the world,” says Iosifidis.

The noise problem has dogged aeronautical innovators looking to create a follow-up to the Anglo-French Concorde project since the aircraft retired in 2003.

Several attempts to revive supersonic air travel are ongoing.

Japan Airlines invested $10 million into Boom Technologies, a Denver-based start-up that also hopes to revive supersonic air travel in the next decade.

Meanwhile, Spike Aerospace is hoping to test its S-512 Supersonic Jet by the end of 2018.