The application of the turbine engine to high flight speed missiles is considered and the advantages that such missiles have are discussed. In order to show examples of high flight speed turbine engines a straight turbojet engine and a turbojet-ramjet engine are described briefly. The performance at a Mach 4.0 cruise condition is shown for a sample set of assumptions. The acceleration phase of the mission is then considered and the differences in characteristics between a high specific thrust engine and a low specific thrust engine are described. The inlet and exit matching problems over the flight speed range are also illustrated. The suitability of the turbine engine for powering missiles with different ranges and different engine requirements is discussed. It is indicated that several important missions can be carried out by turbine engine powered missiles of low gross weight.