It seems as if NASA has decided to make its new supersonic hope, the X-59, a cult object. Fans were able to make a paper model in advance. The presentation of the jet could be followed in watch parties all over the world on Friday evening. And the look is impressive: a video shows the plane rolling out of the hangar dramatically like in the Bond film.
The incredibly long, pointed nose, which pushes itself into the picture centimeter by centimeter, is part of the design, which is intended to reduce the sonic boom, along with the missing cockpit. The typical sound that causes windows to shake occurs on the ground because the aircraft pushes air in front of it, thereby generating shock waves. Andreas Strohmayer is a professor of aircraft design at the University of Stuttgart. He says: “There are shock waves on all edges of the aircraft: at the tip, at the cockpit window, at the base of the wing, the tip of the wing, at the end of the wing, at the end of the fuselage.” These pressure jumps mix on the way to the earth’s surface and produce a large bang.
NASA now wants to turn this noise into a quiet pop. “They try to equalize the geometry so that the shock waves do not arrive at the earth’s surface mixed and the shocks are minimized.” Test flights will show how well this works. The jet was completed last July, followed by ground tests. The first flight of the X-59 is scheduled for this year. The test flights are also intended to show how dry, moist, warm or cold air affects the noise.
In Palmdale, California, NASA and the defense company Lockheed Martin have now presented the machine after almost six years of development. A crumpled white curtain reveals the X-59. Externally, the aircraft only differs from the video from summer 2023 in its gray paint. The nose of the X-59 makes up almost half of its 30 meter length. With lavishly produced clips in which developers and engineers are interviewed, accompanied by epic orchestral music, the presentation is intended to usher in a new era of aviation.
The X-59 is intended to become a passenger aircraft, but at the moment it is still a research platform to study the sonic boom. Lockheed Martin is building the prototype on behalf of NASA for $250 million. In its less prominent role as an aviation agency, NASA has launched a mission called QueSST: Quiet Super Sonic Technology.
NASA explains the mission’s somewhat surprising goal on its website: “Quesst aims to provide regulators with data that would help change regulations for commercial supersonic flight over land.” The quiet X-59 jet is intended to make supersonic flight legal again.
Research is even being carried out on hypersonic aircraft
In the race for the first supersonic passenger aircraft in the 1960s, Europe and the Soviet Union had left the USA behind: on New Year’s Eve 1968, the first civilian supersonic aircraft, the Tupolev Tu-144, flew, and the Anglo-French Concorde took off a good two months later. In 1973, the US Federal Aviation Administration (FAA) banned supersonic flights over land, probably to slow down the success of the Concorde. “It was a small sting at the time, for economic reasons. But it’s still there now,” says Andreas Strohmayer.
NASA is not alone in its new enthusiasm for super-fast aircraft. The Japanese space agency Jaxa is also developing a supersonic aircraft, and the Italian aerospace center CIRA is even researching hypersonic aircraft that should reach Mach 5 or faster. The plans of the US start-up Boom are also ambitious: from 2025 it wants to produce the supersonic jet “Overture”, which offers space for 55 passengers. American Airlines and United Airlines have already pre-ordered it. The company Spike Aerospace is also planning to design a supersonic aircraft; Aerion Supersonic went bankrupt with a similar project in 2022.
“Supersonic passenger flight is certainly possible, as the Concorde and the Tupolev Tu-144 have already shown,” says Strohmayer. “But we’re no longer in the 1960s, where it was all about ‘faster, higher, further’.”
The X-59 is designed to fly at Mach 1.4, which is 1.4 times the speed of sound. This corresponds to around 1,730 kilometers per hour. A Boeing 747 flies at around 900 kilometers per hour. The faster flight consumes more fuel, says Andreas Strohmayer: “On the one hand because the speed requires greater thrust and on the other hand because supersonic jets fly higher than normal passenger flights and therefore require more fuel.” According to manufacturer Lockheed Martin, the X-59 will fly at an altitude of 16.7 kilometers, compared to the approximately 10 kilometers altitude of a Boeing 747. This brings with it the next problem: “It’s not just more emissions; the higher in the atmosphere they are emitted, the longer they stay,” says Strohmayer. In the troposphere, where passenger flights fly, it is a maximum of months. Above the tropopause, where supersonic jets fly, it would take years, decades and centuries.
“I don’t think supersonic flight is in keeping with the signs of the times,” says Strohmayer. “Flying faster by a few rich people would endanger the climate for everyone.” Nevertheless, he believes that supersonic aircraft will bring people across the Atlantic again at some point: “There are certainly people who want to fly faster and have something that others don’t have. The supersonic business jet luxury item will probably exist.”
In Europe, the signs are more towards “Clean Aviation”, the attempt to make air transport more environmentally friendly: In the EU project “MOREandLESS”, the German Aerospace Center is also looking for ecologically sustainable supersonic flight. “The greatest hope lies in so-called sustainable aviation fuels,” says Andreas Strohmayer, artificial fuels such as e-fuels, which are supposed to be produced in a CO₂-neutral manner and are also controversial. But batteries are still too large to be used for flights, and fuel cells emit water vapor, which also has an impact on the climate in the atmosphere.