Until its retirement 13 years ago, the supersonic Concorde was plagued by two major problems: inefficiency and noise (the sonic booms it produced got it banned from over-land cruising). Now, heavyweights like Virgin and Airbus are planning to tackle supersonic speeds, and NASA began designing a "low boom" supersonic jet this year. But no one is as close as aircraft manufacturer Aerion Corporation, which is developing the AS2.

Quiet Cruise

When air molecules slam into a supersonic jet, they create a high-pressure wake that reaches the ground as a startling "ba-boom." By slowing down its cruise speed to Mach 1.2 (the Concorde's was Mach 2), the AS2's wake will dissipate before it reaches civilization.

Straight and Carbon-Strong Wings

Typical supersonic wings sweep back to create a triangular shape. That design creates lift—but also drag-producing air eddies toward the back of the wings. The AS2's wings jut straight out from the fuselage and, thanks to ultrastrong carbon fiber, have a thinner contour. This lets air travel in straighter lines, reducing overall drag by about 20 percent.