Herman Potočnik (pseudonym Hermann Noordung) (December 22, 1892 - August 27, 1929) was a Slovene rocket engineer and pioneer of cosmonautics (astronautics). He is chiefly remembered for his work addressing the long-term habitation of space.
At the end of 1928, he published his sole book, Das Problem der Befahrung des Weltraums - der Raketen-Motor in Berlin. In 188 pages and 100 illustrations, Potočnik set out a plan for a breakthrough into space and the establishment of a permanent human presence there. He conceived a space station in detail and calculated its geostationary orbit. He described the use of orbiting spacecraft for detailed observation of the ground for peaceful and military purposes, and described how the special conditions of space could be useful for scientific experiments.
A proposal was made in the late 1990s to name the International Space Station after him, but was not taken up.
The meaning of his German-like pseudonym Noordung is still a mystery, but some suggest that he used it to show the problems of chaos (German: Ordnung, "order"; ordunga in Slovene colloquial language). Assuming that the initial "N" may have been intended to mean negation, the name would mean "without order".