The Physics of Rockets

Although the Chinese are credited with the use of gunpowder rockets as early as several centuries B.C., and Hero of Alexandria invented a steam jet propulsion device about 100 B.C., most of the serious effort to develop rockets has occurred in the last three decades. Goddard in America made a complete study of rocket performance in 1914. The German all-out rocket program commenced in 1935 culminating in the V-2, which was first fired in September of 1944. Since 1938, intensive rocket research has been carried out by a number of American agencies, including a basic theoretical contribution by Malina in 1940. The present paper will concern itself only with that type of jet propulsion device designated as a "pure" rocket, i.e., a thrust producer which does not make use of the surrounding atmosphere. This restriction excludes propulsive duct devices such as the "turbojet" engine used in jet propelled airplanes of the P-80 type. No attempt will be made to discuss the aerodynamics of bodies moving at supersonic speeds, the electronic problems of rocket missile guidance and control, the measurement of physical quantities in the upper atmosphere, or the properties of weapon rockets. Even omitting these interesting fields, the science of rocketry embraces many phases of physics and chemistry, as will appear in later sections.