NASA鈥檚 experimental X-59 plane is scheduled to take to the skies early in 2023 to see if it can break the sound barrier without creating a huge sonic boom. If it works, it could lead to the return of commercial airliners that can travel faster than the speed of sound, as Concorde used to do.
The , which will take off from Palmdale, California, is built by Lockheed Martin but is the product of decades of supercomputer simulations and supersonic wind-tunnel tests at NASA鈥檚 Langley Research Center in Virginia.
The plane is a strange-looking beast: at 30 metres long and just 9 metres from wingtip to wingtip, its skinny, paper-dart shape is dominated by an outsized, proboscis-like nose. The pilot can only see ahead via a video camera because the slant of the nose is too great for a decent-sized cockpit window.
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The shape is designed to reduce the sonic boom created when a plane breaks the speed of sound in air, which is 343 metres per second at 20掳C (68掳F). The 105-decibel sonic booms that Concorde produced could be toned down to a 鈥渟oft thump鈥� of 75 decibels in the X-59. This is roughly
The chief trick to creating this Quiet Supersonic Technology () lies in sculpting the plane so that the shockwaves generated by its nose are prevented from coalescing with those produced by its tail. This is why the nose is so elongated: to push out the front shockwaves as far as possible from the rear ones.
The merger of the waves by the time they reach ground level is what causes us to hear the loud boom, says聽, the X-59鈥檚 deputy project manager for technology at NASA Langley.
Initial flights of the single-pilot plane are scheduled to start in early 2023. Seven to nine months later, the aircraft will set off on a tour of the US, making supersonic flights over communities in rural and urban locations. Thousands of people will then be polled by NASA on whether they think the sound level is acceptable.
If the noise-quelling measures are deemed to work, NASA hopes aircraft makers will be able to adopt them in a new generation of supersonic airliner designs.
The only commercial supersonic airliners to have flown to date were Concorde and a flawed Soviet Union competitor, the Tupolev Tu-144, both of which are now retired. Concorde鈥檚 economic prospects were hampered because aviation regulators didn鈥檛 allow it to fly lucrative supersonic routes over land due to the noise and building damage its sonic booms caused.
The X-59鈥檚 chief engineer,聽, is confident they have cracked the noise and damage issue. 鈥淏ased on all of our computational fluid dynamics tools, in which we鈥檝e propagated the pressure disturbances all the way to the ground from flight altitude, we believe we know how to do it,鈥� he says. 鈥淲e鈥檒l see when we go fly.鈥�
