NASA announced this week that it is one step closer to testing successful sonic-boom-mitigation technology on a demonstration aircraft, a move viewed as critical to repeal of the current prohibition of supersonic flight over land. That prohibition is viewed by many as a limiter on the supersonic business jet market.

The agency has completed the preliminary design review (PDR) of its Quiet Supersonic Transport (QueSST) aircraft design. QueSST is the initial design stage of NASA’s planned low boom flight demonstration (LBFD) experimental airplane. NASA partnered with lead contractor Lockheed Martin in February 2016 for the QueSST preliminary design.

Last month, a scale model of the QueSST design completed testing in an eight-by-six-foot supersonic wind tunnel at NASA Glenn Research Center in Cleveland, Ohio. Completing the PDR clears the way for NASA to solicit competitive bid build proposals later this year for construction of the actual demonstration aircraft.

Flight testing of an LBFD X-plane could begin as early as 2021. Remaining design validations scheduled for the next few months include a static inlet performance test and a low-speed wind tunnel test at NASA Langley Research Center in Hampton, Virginia.