More than fifty years ago, the United States barred civilian overland supersonic flights to shield the public from the sonic boom produced by these aircraft, but last year Donald Trump rolled back that rule: he aims for the U.S. to become the first country—before China—to offer commercial supersonic flights over land.
So NASA has plunged into a project named the ‘Quesst Mission’. Using the X-59 supersonic aircraft, they intend to prove that it is possible to travel faster than sound without the brutal noise or “sonic boom” accompanying the flight. In other words; they want to figure out how to reduce that deafening noise so that commercial flights can cruise at speeds above 1,400 km/h.
NASA wants to know what people hear when the X-59 flies
Although NASA’s trajectory in the study of supersonic flight goes back more than 70 years, the X-59’s first flight occurred last year, when it was flown with a chase aircraft F-15 capable of following it and acting as an extra eye. At the controls were test pilots Nils Larson and Jim Less.
Since then, NASA’s X-59 has completed dozens of flights, and in June it first exceeded the speed of sound, laying the groundwork to demonstrate its quiet supersonic capabilities by the end of this year. A task quite challenging given the damage that sonic booms can cause to people, animals and infrastructure.
NASA test pilot Jim “Clue” Less took off and landed at Edwards Air Force Base in California. The flight lasted 81 minutes and reached a speed of 1,492 km/h, during which the team focused on evaluating flight characteristics at both subsonic and supersonic speeds.
This speed and altitude provide the baseline for the X-59 as it flies over several American communities, enabling NASA to collect data on how people might perceive its slight noise. NASA will then share these data with both U.S. and international regulators to help establish data-driven noise standards, paving the way for a viable future market for land-based commercial supersonic flights.
What is a sonic boom? When an aircraft travels at or above the speed of sound, air molecules cannot move out of the way quickly enough, so the pressure waves merge to create a large shock wave that people on the ground hear as a sonic boom.
Computational Fluid Dynamics and wind tunnels. To understand how to dampen the noise, scientists rely on computational fluid dynamics—a computer-based modeling approach researchers use to show where air molecules are displaced by a moving aircraft and generate noise.
These models can help engineers identify the best points to modify an aircraft’s design in order to reduce noise. In the image above, the red color indicates where noise is produced most on an aircraft. Additionally, scientists use wind tunnels to test how aircraft models will behave in flight.
The mission will last until 2029.
Images | NASA
