When the U.S. looked to build a supersonic airliner, the Lockheed L-2000 came within reach of becoming a commercial mainstay.

The Concorde suffered a fatal crash in July 2000, which spurred the end of the supersonic jet program. What's next for mach ...

Concorde, the first and only supersonic commercial jetliner, operated from 1976 to 2003. Flown by royals, celebrities, and executives, it was discontinued because of high operating costs.