NASA is exploring the potential for a supersonic jet that could take commercial passengers from London to New York in 90 minutes.
The US space agency's Quesst mission was launched in 2016, primarily to design an aircraft with technology that reduces the loudness of a sonic boom: that's what we hear on the ground when a plane travels faster than sound.
They are so powerful that operating an aircraft capable of producing them above populated areas is banned.
NASA’s project has resulted in X-59, a Concorde-like research jet designed by defence contractor Lockheed Martin that can cruise at 937mph at an altitude of 55,000ft without generating an unacceptable noise level.
It hopes to run test flights over US cities in 2024 and gather data on locals' response to the sound, with the hope it could inform changes to aviation rules.
This week, NASA's Glenn Research Center revealed it had investigated the business case for supersonic travel, potentially allowing for a jet to zip over the Atlantic at between 1,500 and 3,000mph.
Today's large airliners fly at roughly 600mph, and a London to New York flight takes around eight hours on average.
Now, companies including Boeing and Rolls-Royce have been contracted to come up with a potential roadmap for making such trips a reality - including design concepts for supersonic passenger planes.
Mary Jo Long-Davis, manager of NASA's hypersonic technology project, said: "The design concepts and tech roadmaps are really important to have in our hands when the companies are finished.
"We are also conscious of the need to account for safety, efficiency, economic, and societal considerations.
"It's important to innovate responsibly so we return benefits to travellers and do no harm to the environment."
'A new chapter in supersonic flight'
The announcement comes just weeks after X-59 was moved from its construction site to the so-called flight line, the space between the hangar and runway at a Lockheed Martin facility in California.
The firm, which was handed a £187.5m contract to build the plane, has started a series of ground tests ahead of a potential trial flight later this year.
Peter Coen, NASA's Quesst mission integration manager, has said his team are "ready to write a new chapter in the history of supersonic flight".
It would follow in the contrails of Concorde, the world's first supersonic airliner.
It holds the record for fastest commercial flight between New York and London, completing it in two hours, 52 minutes and 59 seconds in 1996.
The planes were grounded in 2003, as operators British Airways and Air France blamed a downturn in demand and increasing maintenance costs.
The final Concorde departed three years after an Air France Concorde flight 4590 crashed into a hotel shortly after take-off from Paris - killing 109 people on board and four people on the ground.
NASA is not alone in researching supersonic commercial travel. United Airlines has partnered with start-up firm Boom Supersonic to potentially bring it back to travellers, while Virgin Galactic revealed designs for a supersonic passenger plane in 2020.–news.sky.com