The Lockheed Martin Skunk Works began developing the QSST in May 2001 under a $25-million contract from SAI.

7,402 km), the two-engine gull-wing aircraft was designed to create a sonic boom only 1% as strong as that generated by the Concorde.

[3] SAI invited engine proposals from General Electric, Pratt & Whitney and Rolls-Royce.

[3] SAI had planned to select an engine once an international consortium to manufacture the jet was completed, achieve first flight in 2017, and begin customer deliveries by 2018.

The reduction in sonic-boom energy is achieved by increasing the ratio of length to wingspan, using canards, and ensuring that the individual pressure waves generated by each part of the aircraft structure reinforce each other less significantly, producing a light rumble on the ground without an objectionable sonic boom like conventional supersonic aircraft.