sonic booms

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Ever since Chuck Yeager blew through the sound barrier in his X-1 in 1947, residents living near testing ranges have been bombarded by sonic booms. The thunderous booms rattle windows and scare pets, and are one of the reasons the Concorde never flew across the continental U.S. In "Whooshhh!" a story that appeared in our July 2004 issue, writer Bill Sweetman described a recent experiment with a modified F-5 fighter jet suggesting that with careful engineering tweaks, the sonic boom intensity can be reduced to tolerable levels.

Aerospace engineer David Graham and his three colleagues had a deadline, and a little brown tortoise was putting it in jeopardy. In a few hours, as the sun rose over the Mojave Desert on an August morning last year, two Northrop Grumman F-5E fighter jets would come racing over the horizon. Flying 30,000 feet above Harper Dry Lake and traveling at 920 mph, the airplanes would be trailing long sonic boomsthe distinctive aural signatures of supersonic flight that ordinarily make high-speed passages over land impossible.