Supersonic silence: Nasa to build low-boom aircraft

The supersonic X-plane will fly at speeds of over 1500 km/h and make a sound as quiet as a car door closing

Nasa’s aeronautical innovators have decided to move at supersonic speed while keeping everything silent. For the first time in decades, the agency has designed a piloted X-plane from scratch. The aircraft will fly faster than sound with “the latest in quiet supersonic technologies”.

The Lockheed Martin Skunk Works X-plane design will generate a gentle, supersonic heartbeat instead of a sonic boom  — PRNewsfoto/Lockheed Martin Aeronautics NASA supersonic
The Lockheed Martin Skunk Works X-plane design will generate a gentle, supersonic heartbeat instead of a sonic boom  — PRNewsfoto / Lockheed Martin Aeronautics

On April 2, Nasa awarded a $247.5 million contract to the Californian Lockheed Martin Aeronautics Company. By the end of 2021, they are to build and deliver the X-plane to the agency’s Armstrong Flight Research Center in California.

“Under this contract, Lockheed Martin will complete the design and fabrication of an experimental aircraft, known as an X-plane, which will cruise at 55,000 feet (16.8 km) at a speed of about 940 mph (1513 km/h) and create a sound about as loud as a car door closing, 75 Perceived Level decibel (PLdB), instead of a sonic boom,” Nasa said in an official statement.

The key to point of this mission is to demonstrate the ability to fly at the speed of sound while generating sonic booms so quiet, people on the ground wouldn’t even notice it. This approach is known as the Low-Boom Flight Demonstrator.

“It is super exciting to be back designing and flying X-planes at this scale,” said Jaiwon Shin, Nasa’s associate administrator for aeronautics. “Our long tradition of solving the technical barriers of supersonic flight to benefit everyone continues.”

The X-plane is supposed to reduce the noise of the boom with its unique design that allows it to generate weaker supersonic shockwaves. Conventional aircraft create shockwaves that “coalesce as they expand away from the aeroplane’s nose and tail, resulting in two distinct and thunderous sonic booms,” Nasa explains.

In comparison to the classic design, the X-plane’s shape prevents the shockwaves from coming together. Therefore, the waves reach the ground separately, creating nothing but a quick series of soft thumps.

Once the aircraft is delivered, Nasa will perform additional flight tests to evaluate the outcomes of the quiet supersonic technology design.  The agency will assess whether the aircraft performance is robust, and it’s safe to operate in the National Airspace System.

Beginning in mid-2022, Nasa will fly the X-plane over select US cities and collect data about community responses to the flights.

“There are so many people at NASA who have put in their very best efforts to get us to this point,” Shin said.

Thanks to their work so far and the work to come, we will be able to use this X-plane to generate the scientifically collected community response data critical to changing the current rules to transforming aviation!”