The spaceplane will take off using a rocket-powered rail sled, which is about two miles long. This sled – which would sit on top of a runway – accelerates the Radian One to 537mph. But the ...

The quest for the sound barrier was a big thing in the 1960s with the advent of jet and rocket-powered cars seeking to beat the standing 403mph (648.73km/h) record set by English driver Donald ...

If Mach 1+ sounds too slow for that transatlantic flight, how about Mach 22.5, or 17,400 mph? That may soon be an option, thanks to a fleet of spaceplanes readying to take flight. While the latest ...