In New Mexico the United States Air Force is testing the strength of certain elements at hypersonic speeds. Wiring, coating and other materials must be tested for durability under high acceleration and different speeds. The Air Force uses the Holloman High Speed Test Track, which was completed in 1949, to conduct their tests.
The High Speed Test Track is 10 miles long and was regularly used to test weapons and other military related devices. As seen in the video below a sled is tested well over Mach 5 (3836.35MPH.) The test concluded that the sled ran at 6,599 MPH, but to the naked eye it looks like nothing but a flash if light.
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