The US space agency 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, otherwise known as an X-plane.
The QueSST design is capable of fulfilling the LBFD aircraft's mission objectives, which are to fly at supersonic speeds, but create a soft "thump" instead of the disruptive sonic boom associated with supersonic flight today.
The LBFD X-plane will be flown over communities to collect data necessary for regulators to enable supersonic flight over land.
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 the 8x6-foot supersonic wind tunnel at NASA's Glenn Research Centre in Cleveland.
"Managing a project like this is all about moving from one milestone to the next," said David Richwine, manager for the preliminary design effort under NASA's Commercial Supersonic Technology Project.
"Our strong partnership with Lockheed Martin helped get us to this point. We're now one step closer to building an actual X-plane," said Mr Richwine.
After the success of completing the PDR, NASA can start the process of soliciting proposals and award a contract early next year to build the piloted, single-engine X-plane.