History of Rockets - Theories of Interplanetary Rocketry

Theories of Interplanetary Rocketry

In 1903, high school mathematics teacher Konstantin Tsiolkovsky (1857–1935) published Исследование мировых пространств реактивными приборами (The Exploration of Cosmic Space by Means of Reaction Devices), the first serious scientific work on space travel. The Tsiolkovsky rocket equation—the principle that governs rocket propulsion—is named in his honor (although it had been discovered previously). He also advocated the use of liquid hydrogen and oxygen as fuel, calculating their maximum exhaust velocity. His work was essentially unknown outside the Soviet Union, but inside the country it inspired further research, experimentation and the formation of the Society for Studies of Interplanetary Travel in 1924.

In 1912, Robert Esnault-Pelterie published a lecture on rocket theory and interplanetary travel. He independently derived Tsiolkovsky's rocket equation, did basic calculations about the energy required to make round trips to the Moon and planets, and he proposed the use of atomic power (i.e. radium) to power a jet drive.

Robert Goddard began a serious analysis of rockets in 1912, concluding that conventional solid-fuel rockets needed to be improved in three ways. First, fuel should be burned in a small combustion chamber, instead of building the entire propellant container to withstand the high pressures. Second, rockets could be arranged in stages. And third, the exhaust speed (and thus the efficiency) could be greatly increased to beyond the speed of sound by using a De Laval nozzle. He patented these concepts in 1914. He also independently developed the mathematics of rocket flight. He proved that a rocket would work in a vacuum, which many scientists did not believe at the time.

In 1920, Goddard published these ideas and experimental results in A Method of Reaching Extreme Altitudes. The work included remarks about sending a solid-fuel rocket to the Moon, which attracted worldwide attention and was both praised and ridiculed. A New York Times editorial suggested that Professor Goddard: "does not know of the relation of action to reaction, and the need to have something better than a vacuum against which to react—to say that would be absurd" but that "there are such things as intentional mistakes or oversights."

Goddard's historical impact was diminished by the fact that he worked much in secret, though he offered his services to the military but was mostly ignored. This secrecy was prompted in part by his bad experience with the press and in part by his belief that his ideas were being plagiarized by foreign scientists. He was also in bad health and did not want to waste time helping amateurs and arguing with other scientists who did not understand this new science.

In 1923, Hermann Oberth (1894–1989) published Die Rakete zu den Planetenräumen ("The Rocket into Planetary Space"), a version of his doctoral thesis, after the University of Munich rejected it.

In 1924, Tsiolkovsky also wrote about multi-stage rockets, in 'Cosmic Rocket Trains'