The world got quite a bit smaller when the supersonic Concorde passenger jet was introduced in 1969. The Concorde could travel at  twice the speed of sound. It was grounded in 2003, leaving no commercial options for travel at the speed of sound. Supersonic air travel may be on its way back. CNN reports Japan Airlines has invested 10 million dollars in a Denver based firm called Boom Tehcnologies. The airline has reportedly pre-ordered 20 supersonic aircraft. It comes as no surprise Richard Branson's Virgin Group holds options as well. The new jets will reportedly be capable of reaching Mach 2.4.