AN experimental Nasa airplane that "quietly" flies faster than the speed of sound could zoom from London to New York in around 3.5 hours.
The supersonic aircraft is called the X-59 Quesst – and will cruise at altitudes of 55,000 feet at speeds of 937mph.
That's far above the speed of sound, which is around 767mph.
And it's well above the 575mph cruising speed of a Boeing 747 at 35,000 feet.
Importantly, the X-59 Quesst would have a low enough noise level to be able to fly over land.
Currently, commercial passenger planes are banned from going at such speeds – if they were able to – over land in the UK and US on account of the noise levels.
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But Nasa has teamed up with Lockheed Martin to build an aircraft that solves this problem – just by being quiet.
"We had a commercial supersonic aircraft, the Concorde," explained Lori Ozoroski, a project manager at Nasa, speaking during an official podcast.
"But it was limited during its flights that it could not fly, say into, you know, somewhere in the middle of the U.S. You were not allowed to fly supersonic over land.
"So most of the flights were back and forth just over the ocean. And so again, that ban has been in place for 50 years, over 50 years in the U.S. A lot of international countries as well have similar bans.
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"And so the whole goal of this research that we’re doing right now is to lift that ban and set a speed limit for commercial supersonic aircraft rather than a speed limit."
The airplane is long and narrow, and is designed specifically to reduce noise.
And it's expected to begin proper flight testing as soon as this year.
According to Cathy Bahm, who also works on the project at Nasa, it would simply "create a quiet thump on the ground".
Lori added: "The sound level is more like – we’ve done studies – it’s more like a car door closing, you know, across the street at your neighbor’s house rather than the very loud typical sonic boom."
Despite being an "experimental" craft, the X-59 is well on its way to being trialled in flight.
It's been through structural testing to see if it can withstand the right forces.
And there's an ejection seat that's been installed and inspected – ready for a potential pilot bail-out, if needed.
Next comes engine testing, and then eventually a full manned flight test.
"In just a few short years we’ve gone from an ambitious concept to reality," said Pam Melroy, Nasa's deputy administrator.
The cockpit is located almost halfway down the length of the aircraft – and does not have a forward-facing window
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"NASA’s X-59 will help change the way we travel, bringing us closer together in much less time."
Once flight tests are completed, Nasa will then fly the aircraft over several US cities.
The agency will then be able to capture data about how much sound is really being generated on the ground – and how people feel about it.
Nasa hopes that its breakthrough craft will inspire future generations of airplanes with similarly quiet designs.
"At 99.7 feet long and 29.5 feet wide, the aircraft’s shape and the technological advancements it houses will make quiet supersonic flight possible," Nasa explains.
"The X-59’s thin, tapered nose accounts for almost a third of its length and will break up the shock waves that would ordinarily result in a supersonic aircraft causing a sonic boom.
"Due to this configuration, the cockpit is located almost halfway down the length of the aircraft – and does not have a forward-facing window.
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"Instead, the Quesst team developed the eXternal Vision System, a series of high-resolution cameras feeding a 4K monitor in the cockpit."
NASA'S X-59 TIMELINE
Here's the official timeline from Nasa...
Phase 1: Aircraft Development
2018-2024
NASA anticipates that initial flights to prove performance and safety (also known as “envelope expansion”) will take about nine months. At the successful conclusion of these flights, NASA will officially take delivery of the aircraft from Lockheed Martin.
Phase 2: Acoustic Validation
2025
NASA will fly the X-59 within the supersonic test range over NASA’s Armstrong Flight Research Center and Edwards Air Force Base in California to prove the quiet supersonic technology works as designed, aircraft performance is robust in real atmospheric conditions, and the X-59 is safe for operations in the National Airspace System.
Phase 3: Community Response Study
2026-2028
The agency will use the X-59 to gather data on how effective the quiet technology is in terms of public acceptance. This will be done by flying over select U.S. cities beginning in 2026 and asking residents to share their response to the sound the X-59 produces.
Final Data to Regulators
2030
NASA will provide a complete analysis of the community response data to U.S. and international regulators for their use in considering new sound-based rules regarding quiet supersonic flight over land. Such rules could enable new commercial cargo and passenger markets in faster-than-sound air travel. This will be turned over when the mission ends.
Nasa says that the aircraft is due to set off "for the first time later this year".