Once the habitat of the legendary Concorde commercial jet, the realm of supersonic flight has been relegated primarily to military aircraft for years now, but Lockheed Martin aims to change all that thanks to funding from NASA and their new X-59 program.
The premise behind the X-59, also known as the Quiet Supersonic Technology (QueSST) aircraft, is simple: develop and build an aircraft capable of achieving supersonic speeds without also producing the tell-tale sign of a Mach-capable aircraft: a sonic boom.
In the years since the Concorde last flew, some misconceptions have cropped up regarding supersonic flight for the everyman. Many believe it was a safety issue that killed off the world’s fastest commercial airliner, largely due to a 2000 crash that killed 113 people right near the end of the plane’s tenure — but the real issues were economic, and as may come as a surprise, audible. The economics were simple: the plane wasn’t very fuel efficient and was extremely expensive to operate. How expensive? Adjusted for inflation, a ticket from New York to Los Angeles cost passengers just about $15,000.
Worse, while the Concorde could theoretically get you from New York to LA in just about three and a half hours, it was legally barred from doing so. Supersonic flight is actually illegal over the United States because of the massive sonic booms aircraft create as they break the sound barrier. Imagine a boat traveling slowly through the water — as the boat moves forward, it creates waves that disperse around its bow. Once the boat gets moving faster, however, those small waves can no longer move out of the way fast enough and the boat instead creates a single wake. A wake is really just one large wave formed out of all the small disruptions the boat produces in the water, compounded.
Now imagine an aircraft moving through the air in much the same way. When traveling at below 700 miles per hour or so, the sound waves produced by the aircraft can ripple away from its nose at their own pace. Once you cross that barrier into Mach 1, however, the waves can’t dissipate individually and instead manifest as a singular compounded wake. That “wake” is a sonic boom — or one single, massive sound wave. These sonic booms are more than just loud, they’ve been known to damage property, shatter windows, and even cause worse structural damage — so the U.S. government has banned aircraft from breaking that barrier over land to prevent such damage from occurring.
Military aircraft are only occasionally granted permission to break the sound barrier over the U.S. in circumstances pertaining to national security. F-15s out of the Portland National Guard Base in Oregon were authorized to go supersonic in August of this year, for instance, when a ground worker commandeered a Bombardier Dash 8 commuter airliner at the Seattle/Tacoma Airport. That pilot ended up crashing the plane on his own.
However, now NASA and Lockheed Martin believe they can put an end to prohibition of supersonic flight over the U.S. by developing a new aircraft that can achieve those speeds without producing that sound “wake” that manifests as a sonic boom. By elongating the nose of the aircraft and adapting the fuselage shape, control surfaces, and engine inlet, they believe they can replace sonic “booms” with sonic “thuds” that would be barely audible on the ground.
“This aircraft has the potential to transform aviation in the United States and around the world by making faster-than-sound air travel over land possible for everyone,” NASA administrator Jim Bridenstine said in a press release about the Lockheed deal. “We can’t wait to see this bird fly!”
With a $250 million investment secured through NASA earlier this year, Lockheed Martin now believes they’ll be conducting early demonstration flights in just three years. If those flights are successful, NASA hopes the technology can be adopted by more commercial enterprises and, eventually, the laws banning supersonic flight over land will be lifted in favor of a new era of faster-than-sound commuter travel.
And hopefully for less than $15,000 a ticket.