Imagine a hypersonic passenger aircraft that would cut the journey time between London and New York to around two hours. At Mach 5, or five times the speed of sound, the aircraft would complete a trip across the Atlantic in around 120 minutes. Mach 5 is more than twice as fast as the cruising speed of Concorde…

via Reaction Engines’ Mach 5 engine is just the tip of the new aerospace boom — TechCrunch