While supersonic planes haven’t been available to commercial travelers since 2003, speed freaks can revel in the fact that several new supersonic planes are currently in development.Boeing, Gulfstream and NASA are collaborating on a plane nicknamed the “Son of Concorde,” which would be capable of flying around 2,500 miles per hour. That’s almost twice the speed of the original Concorde, and means a trip from London to Sydney, Australia, would only take four hours, about a fifth of the time it currently takes. The jet would use lighter materials, state of the art engines and a redesigned fuselage to attain the fast speeds.Separately, the Aerion Corporation is working on a new 12-passenger supersonic business jet that would fly at about Mach 1.6, or about 1,200 mph. That’s almost twice as fast as the top speed of a Boeing 747, which is around 650 mph. So a flight from New York to Paris would take about 4 hours and 15 minutes – three hours shorter than current subsonic travel times. The challenge with any new supersonic plane is reducing noise from sonic booms – the loud bangs made by a supersonic plane’s sound waves. Commercial supersonic planes are banned from flying over land in many places because the sonic booms are so distracting to the people below. Researchers at NASA are experimenting with various plane shapes to find the quietest option, which may include a longer, more pointed fuselage than the Concorde had. The need for continued research means supersonic planes won’t be carrying passengers until the start of the next decade, at the earliest. But if it means you can get from London to Sydney in four hours, it will be worth the wait.