Lockheed Martin Skunk Works has begun cutting metal for the first components of its X-59 Quiet Supersonic Technology test aircraft. Earlier this year, NASA selected the famed Skunk Works team to design and build an airframe to experiment with aerodynamics and other techniques for mitigating sonic booms, with an eye toward removing FAA restrictions against supersonic flight over land.

Under Lockheed Martin’s Low Boom Flight Demonstrator program, the X-59 will be flown “to collect community response data” over controlled sites. People on the ground will report their perceptions. The goal is to reduce sonic booms to 75 Perceived Level decibels (PLdB) at the Earth’s surface, equivalent to the sound of a car door closing.

“The long, slender design of the aircraft is key to achieving a low sonic boom,” said Peter Iosifidis, program manager of the Low Boom Flight Demonstrator project. “As we enter the manufacturing phase, the aircraft structure begins to take shape, bringing us one step closer to enabling supersonic travel for passengers around the world.”

First flight of the X-59 is scheduled for 2021. It is designed to fly at approximately Mach 1.23 (940 mph) at 55,000 feet. The design team at Aerion Supersonic is also working with Lockheed Martin and will provide data on its AS2 supersonic business jet, which is designed to be “efficient” at both subsonic and supersonic speeds.