A HYPERSONIC wind tunnel that can test aircraft at 15 times the speed of
sound is being designed by the US Air Force. It will be used to help develop
planes such as NASA’s X-43a Scramjet, due to have its first test flight next
week. The X-43a has a top speed of Mach 10.
Existing wind tunnels can only test planes at speeds of up to Mach 7.
Machines called shock tubes can reach Mach 10, but only for a few milliseconds,
explains Richard Miles, an engineer at Princeton University in New Jersey. So
Miles and his colleague Garry Brown…
