MIAMI – NASA’s X-59 Quiet SuperSonic Technology (QueSST) demonstrator aircraft will fly in 2022 at supersonic speeds with a quieter bang.
In order to assess the public’s acceptability of quiet supersonic flight, NASA plans to fly the X-59 across communities in the United States as early as 2024. However, the agency must first demonstrate that the aircraft is as quiet as its claim. Consequently, NASA will use cutting-edge ground recording equipment to test X-59’s acoustic thumps in the Mojave Desert.
Crystal Instruments Ground Recording System
NASA contracted Crystal Instruments of Santa Clara, California, to provide a high-fidelity sonic boom – and soon, a silent sonic thump. The firm developed a recording device capable of supplying appropriate data to verify the X-59’s acoustic signature.
As reported by Aerospace Magazine, “This will be the first time that we have a single system across NASA to do this research, and it will incorporate a lot of newer technologies to allow us to get this done,” said Larry Cliatt, NASA’s tech lead for the acoustic validation phase of the NASA’s Low-Boom Flight Demonstration mission. “I consider it the next generation of a sonic boom, and soon to be quieter sonic thump, recording systems.”
The Crystal Instruments Ground Recording System will be used by NASA to collect data on sonic booms and thumps, including time, waveform, and spectral data (CI-GRS). Furthermore, the system allows NASA to install custom software and algorithms for real-time sonic thump analysis on the CI-GRS. It may also calculate a variety of acoustic parameters, such as perceived sound intensity, which is currently used to assess the loudness of sonic booms.
“What we are building is a data acquisition system that will use the latest advancements in technology, with cutting edge hardware and software capabilities, so that NASA can capture the high-quality sonic boom data they need,” said Darren Fraser, Crystal Instruments vice president of sales.
NASA Armstrong will obtain the first CI-GRS units for the initial flight trials. Other units, such as a 30 Nm ground microphone array, will be installed outside Edwards Air Force Base. The next round of Carpet Determination in Entirety Measurements flights, or CarpetDIEM, will take place in the latter. The next CarpetDIEM flights are scheduled for late 2021, according to NASA.
These flights will be similar to the X-59’s acoustic testing. After that, NASA Armstrong aircraft fly over the array at supersonic speeds to test the units’ ability to capture sonic boom data before recording the X-59’s sonic thumps. The CarpetDIEM test results, on the other hand, will reveal any potential improvements and modifications before the CI-GRS is finalized. To monitor the X-59, NASA uses the final product in up to 70 ground recording stations.
The CI-GRS must also be capable of remote command and control, according to NASA’s requirements. NASA previously installed sonic boom recorders in the field and retrieved the sensors at the end of each test day in previous supersonic acoustic testing attempts. On the other side, a 30-mile-long microphone array in the Mojave Desert faces a technical challenge.
Comments from NASA, CI
“This ground recording system will be more robust and ruggedized when it comes to its operational use, and that’s what we anticipate, with the ability to deploy for several days at a time,” said Cliatt. “These will also incorporate two-way communications so that they can be deployed over a large area when the X-59 flies over communities starting in 2024, so the ultimate total of 175 of these can be controlled from a single remote host.”
“The CI-GRS is going to be a first of its kind, much like the X-59, and I think there will be a lot of firsts in a new age of potential commercial supersonic travel,” said Fraser. “We think this will set the stage for the future, and I think that’s what everybody wants to look toward.”
Featured image: Illustration of the completed X-59 QueSST landing on a runway.Credits: Lockheed Martin