Palmdale, California - NASA has taken another step toward re-introducing supersonic flight with the award Tuesday of a contract for the design, building and testing of a supersonic aircraft that reduces a sonic boom to a gentle thump.

Lockheed Martin Aeronautics Company of Palmdale, California, was selected for the Low-Boom Flight Demonstration contract, a cost-plus-incentive-fee contract valued at $247.5 million. Work under the contract began April 2 and runs through Dec. 31, 2021.

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 at a speed of about 940 mph and create a sound about as loud as a car door closing, 75 Perceived Level decibel (PLdB), instead of a sonic boom.

Once NASA accepts the aircraft from the contractor in late 2021, the agency will perform additional flight tests to prove the quiet supersonic technology works as designed, 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 U.S. cities and collect data about community responses to the flights. This data set will be provided to U.S. and international regulators for their use in considering new sound-based rules regarding supersonic flight over land, which could enable new commercial cargo and passenger markets in faster-than-sound air travel.