Lockheed Martin Corp has released a photo of the first prototype of its supersonic X-plane, the X-59 Quiet SuperSonic Technology (QueSST), during the beginning of the final assembly process.
X-59 QueSST (Quiet Supersonic Technology) will be used to collect community response data on the acceptability of a quiet sonic boom generated by the unique design of the aircraft. The data will help NASA provide regulators with the information needed to establish an acceptable commercial supersonic noise standard to lift the ban on commercial supersonic travel overland.
The X-59 will measure 96 feet long, have a span of 29.5 feet, reach speeds of Mach 1.4, and fly at an altitude of 55,000 feet. A key design requirement of the X-59 is to replicate the noise effects of larger supersonic aircraft so that it can be used to conduct a series of trials over communities in the U.S. to assess the public’s sense of the noise.
The raw structure of a prototype of such a plane, the X-59, has just been assembled at the facilities of NASA contractor Lockheed Martin in Palmdale, California. The 99-foot-long (30 meters), 24,000-pound (10,000 kilograms) one seater might take to the sky as early as the end of 2022, paving the way for a new era of supersonic aviation.
There is no way of not noticing a supersonic fighter jet zooming over your head; the sonic booms are not only loud, but they create vibrations that you can feel. As the plane bursts through the air, it creates soundwaves. But because the plane travels faster than the speed of sound, it surges ahead leaving the waves in its wake crashing into each other. The boom the waves produce, akin to a gunshot, can rattle furniture and even shatter glass.
For example, the supersonic boom produced by the iconic Concorde, the so far only supersonic passenger aircraft in history (retired in 2003), reached 105 decibels, about as loud as a nearby thunderstrike.
The X-59, in comparison, should make no more noise than a car door slamming 20 feet (6 meters) away, according to NASA.
“The amplitude of [the sound wave generated by our] airplane is probably five to eight times lower than that generated by the Concorde,” David Richwine, NASA’s deputy project manager for technology for the Low Boom Flight Demonstrator project, told Space.com. The plane’s NASA designation is the X-59 Quesst experimental plane, with Quesst short for Quiet SuperSonic Technology.
“We’re trying to generate a much more mild, much lower amplitude shock wave and also create a longer rise time to that shock wave on the airplane so that the sound waves don’t come together and create the loud boom as they do on existing supersonic planes,” Richwine said.
This noise reduction might in the future persuade regulators to allow supersonic planes to fly over inhabited areas. So far, because of the disruption caused by the supersonic boom, supersonic air travel is only permitted over the oceans.
This long nose, however, created other technical challenges the engineers had to solve. The smooth and gradual shape of the nose prevents the cockpit of the X-59 from having a direct view of what’s in the front. Instead, the pilot looks at high-definition screens that are fed video input from an external vision system. Advertisement
“The Concorde had a droop nose that allowed the pilots to see the land so that they could actually see where they were landing,” said Richwine. “Thanks to the technical progress that had been achieved since the time that the Concorde had been developed, we could make use of the high-definition cameras and TV screens that we have today. That enabled us to develop a ‘see the land’ capability that is much lighter and simpler.”
NASA hopes the X-59 could pave the way for a new era of supersonic travel that could see people zoom across continents in half the time it currently takes. After the plane takes to the sky for the first time probably at the end of next year, the space agency will run an extensive test campaign that will see X-59 fly over selected communities in the U.S. After each flight, local residents will be asked to answer questions about how much they had noticed the re-engineered supersonic sound.
Aircraft manufacturers could then use the technologies developed as part of the X-59 project to develop larger commercial planes that could carry up to 120 passengers.
