Mach 4.5, in case you were wondering, is 4.5 x the speed of sound. For reference, the now defunct Concorde flew at up to Mach 2. BBC News reports on Airbus’s patent…
hypersonic speed
Reverse-engineered alien technology or human ingenuity? Probably the latter. It seems the US Military is testing a new aircraft that can reach up to Mach 6. It’s first test flight will be…