NASA’s Quesst team is a winner of the 2024 Gizmodo Science Fair for building an experimental aircraft that may travel faster than sound without the ear-splitting sonic boom typically associated with supersonic flight.

The question

Can an aircraft travel supersonically without the sonic boom? It’s been 76 years since the sound barrier was broken and 20 years since the end of supersonic passenger travel, but supersonic flight has always been inextricably tied to the cracking noise of a jet moving faster than sound. NASA’s X-59, with its ultra-long nose, is designed to mitigate the sonic boom, reducing it to a mere sonic “thump.”

“The idea is to not allow a strong sonic boom—strong pressure change—to flow over the ground, which your ears hear as a boom, an explosion,” said Jay Brandon, the X-59’s chief engineer.

The results

After years of tackling engineering challenges and modeling how the aircraft will fly, the team officially revealed the X-59 in January. But the craft hasn’t flown yet. Targeted for sometime this year, the first flight will be a crucial moment for the Quesst team, which has been working on the aircraft for a decade.

Mark F. Mangelsdorf, NASA Armstrong’s deputy chief engineer for the Low Boom Demonstrator Project, said one challenge was creating the ability to predict whether a sonic boom would be produced without testing the plane in the air first.

The extreme needle-nose shape of the X-59 is what should make the sonic thump possible, but that design also made it impossible for the plane to have a windshield. The team solved that challenge by developing the eXternal Vision System (XVS), a set of screens that will allow the X-59 pilot to see out of the plane without forward-facing windows.

© Vicky Leta/Gizmodo Why they did it

The X-59 is 99.7 feet (30.39 meters) long, with a wingspan of just 29.5 feet (9 meters). The aircraft is stiletto-shaped for one simple reason: NASA wants to cut the sound of the sonic boom to a less jarring sonic thump, making it possible for supersonic aircraft to once again travel over land in the United States. Civil supersonic flight over land has been prohibited by the Federal Aviation Administration since 1973, in large part because the public was spooked and annoyed by the ka-blams of military aircraft overhead and the rattling of windows the booms sometimes caused.

“It’s been a long process, from really the 70s all the way up to now, and we’ll see if we have it figured out when we fly this airplane,” Brandon said.

Why they’re a winner

Sonic booms occur when objects travel faster than sound (about 767 miles per hour, or Mach 1). But the X-59 team thinks this aircraft could change that and will test it over a handful of U.S. cities in the late 2020s. The X-59 is designed to cruise at 925 mph (Mach 1.4) at an altitude of about 55,000 feet. When the X-59 goes supersonic, Brandon says it should produce a “door-closing kind of noise” that’s still audible from the ground but less alarming than a true sonic boom.

The return of commercial supersonic flight would drastically reduce travel times around the world, but doing so stateside requires FAA permission, and for that to happen the sonic boom needs to be mitigated. Quesst is the pathway toward future supersonic aircraft designs; though the X-59 won’t carry civilians, it will demonstrate the technological feasibility of supersonic aircraft that don’t cause disruptions to daily life on the ground. But first, it has to fly.

A schlieren image of an X-59 model in NASA Glenn’s supersonic wind tunnel. Image: NASA What’s next

The X-59’s first flight is slated for late 2024. Once it occurs—and assuming it is a success—the Quesst team will continue to run flight tests over Edwards Air Force Base and NASA’s Armstrong Flight Research Center in California through 2025. Then, the aircraft will make a series of flights over select American cities between 2026 and 2027, to prove out whether the sonic boom is sufficiently mitigated for people on the ground. NASA will provide data from this community testing to the Federal Aviation Administration by 2030; the FAA could then change existing regulations precluding commercial supersonic air travel over land in the United States.

“The sonic thump of the X-59 is as quiet as this airplane can get,” Mangelsdorf said. “We could have made it a bit quieter if we had made it longer, but we felt we were quiet enough to perform the mission. And, hopefully, we’ll learn ways to make it quieter once we start flying it.” That’s a fun thought: an even more extreme ratio between the plane’s length and its width.

We won’t know the full extent of the X-59’s success until at least 2027, and that’s assuming it gets into the air this year. But every race has its first steps, and this creative jet could be the machine that ushers in the next era of air travel.

The team

The X-59 team includes Jay Brandon, Peter Coen, David Richwine, Nils Larson, Lori Ozoroski, Walt Silva, and Alexandra Loubeau.

Click here to see all of the winners of the 2024 Gizmodo Science Fair.