The QueSST X-plane will be able to fly up to 1,100mph. Credit: NASA

NASA is developing an experimental supersonic aircraft that will be able to reach speeds of up to 1,100mph and travel quietly enough to fly over land, making it almost as fast, and more direct, than Concorde.

Dubbed the Quiet Supersonic Technology experimental aircraft, or QueSST X-plane, the craft will be designed with a long nose and highly swept wings to reduce the noise it generates.

“This piloted X-plane will look to prove that sonic booms can be turned into sonic thumps, and eventually help make the case for updating the rule against supersonic flight over land,” said Jimi Russell of NASA in April 2017.

A US law came into force in 1973 that outlawed overland supersonic flights, for fear that the 100 decibel sonic booms produced would be too disruptive to people living below flight paths. Since the 1970s, groups have campaigned to have the law reversed, arguing that modern supersonic planes would generate a far less disruptive boom of 80 decibels, one hundred times quieter than those made by Concorde, and that the use of supersonic aircraft would reduce a 40-year stagnation in the speed of commercial flights.

NASA’s plans won approval in the latest US budget, which read: “The Budget fully funds the Low-Boom Flight Demonstrator, an experimental supersonic (faster than the speed of sound) airplane that would make its first flight in 2021.

“This ‘X-plane’ would open a new market for US companies to build faster commercial airliners, creating jobs and cutting cross-country flight times in half.”

Despite its top speed of over 1,353mph, Concorde was plagued by fuel inefficiencies and high economic costs towards the end of its career. The plane burned over 100 tons of fuel flying from London to New York, compared to 44 tons used by today’s Boeing 777, and cost British and French taxpayers over $1.5 billion before operation costs. The X-plans may have to overcome similar issues before its proposed launch date in 2021.