Video: Ultrasonic sled does a mile a second

The U.S. Air Force has released footage from a test of an ultrasonic sled capable of traveling at 6,599 mph (10,620 km/h). Fancy a really short glimpse?

The testing took place at the Holloman Air Force Base in New Mexico. Around two decades ago, the military organization specifically reconstructed the 10-mile (16-km) long straight track for conducting hypersonic tests.

The video here shows the moment the sled passes by, but even at 1/4 the playback speed, all you can see is a brief, bright flash.

Reportedly, the sled accelerated to Mach 8.6 by the time it reached the end of the track. To put things into perspective: the speed of sound equals Mach 5, and hypersonic speeds start at Mach 5.