Original Source: http://wapo.st/1U8z5OT
When planes exceed the speed of sound — 767.269 mph — they generate an “annoying boom,” NASA Administrator Charlie Bolden said at a news conference Monday. Because of this, supersonic flight is prohibited over the United States.
NASA envisions a plane that emits a quieter sonic boom, more like a subtle thump. If supersonic flights were quiet enough to be allowed widely, the appeal of shorter flight times would probably draw travelers and make these planes a viable technology.
“We will be able to achieve the full potential of revolutionary technology and designs that lift aviation to the next level of flying higher, safer and faster,” said Jaiwon Shin, NASA’s associate administrator for aeronautics research.
There have been other efforts at supersonic flight since the sound barrier was first broken in 1947, but none have taken hold.
Most notable was the Concorde, a passenger jet that made its final flight in October 2003 after being a commercial flop. The plane — which traveled at about 1,500 mph — could cross the Atlantic Ocean in 3 1/2 hours. Yet a round-trip ticket between the United States and Europe cost more than $9,000, and the jet was alarmingly loud.
