A flow is called hypersonic if the Mach number is greater than 5. This means that the flow speed is more than five times the speed of sound. In air at room temperature, the speed of sound is around 340 m/s, so a Mach 5 flow would have a flow speed of 1.7 km/s or just over 6,000 km/h. When a rocket launches a satellite into earth orbit, when a probe enters the atmosphere of another planet or when an aircraft is propelled by a supersonic combustion ramjet engine (a scramjet), hypersonic flows are encountered. Hypersonics – from Shock Waves to Scramjets introduces the basic concepts associated with flight at speeds greater than Mach 5 and takes students to the stage where they can analyse the performance of a scramjet engine that might be used in a future access-to-space system.