When launched, cruise missiles have typically reached 500-600 mph (800-965 km/h). However, a new generation of air-breathing supersonic combustion ramjet (scramjet) engines is now emerging after many years of testing and development. These are capable of exceeding Mach 5, or about 3,840 mph (6,150 km/h), making them hypersonic.*
As well as enhancing the responsiveness of a warfighter, the survivability of these missiles as they fly over enemy territory is greatly improved, since they are difficult (if not impossible) to hit at such a high speed.
Now that military use of scramjets has been perfected, commercial use will soon follow. In the 2030s, the first hypersonic airliners begin to appear, capable of travelling around the globe in under four hours.**