The Russian schoolteacher Konstantin E. Tsiolkovsky was the first to state the correct theory of rocket power. He described his theory in a scientific paper published in 1903. Tsiolkovsky also first presented the ideas of the multistage rocket and rockets that use liquid oxygen and hydrogen propellants.

Although the Romanian Oberth and the American Goddard conducted similar research and arrived at comparable conclusions, no evidence suggests that any of the three knew details of the others' work. Therefore, all three of these scientists share the title of "Father of Rocketry."