Here is more information on the Holloman High Speed Test Track. On 2003-04-29 this facility set the world rail speed record at 10,326 km/hour (2.86 km/sec), or around Mach 8.6. Here’s what that looked like.
By comparison, orbital velocity at the altitude of the International Space Station is around 7.66 km/sec, about Mach 23 at sea level.