On September 22, 1905, Austrian rocket propulsion engineer Eugen Sänger was born. Sänger is best known for his contributions to lifting body and ramjet technology. Sänger also perfected a “regeneratively cooled” liquid-fueled rocket engine that used its own fuel, circulating around the combustion chamber, to control engine temperatures.
Eugen Sänger studied civil engineering at the Technical Universities of Graz and Vienna. During his years of study, Sänger was inspired by Hermann Oberth’s book Die Rakete zu den Planetenräumen (By Rocket into Planetary Space) to study civil engineering to aeronautics. Eugen Sänger further joined Germany’s amateur rocket movement, the Verein für Raumschiffahrt (VfR – “Society for Space Travel”) and in 1932, Sänger became a member of the SS and the NSDAP.
When Sänger submitted his thesis on rocket-powered flight, the university rejected it. Sänger was later allowed to graduate, after submitting a more mundane work concerning statics of wing trusses. In the mid 1930s, Sänger published articles on rocket-powered flight for the Austrian journal Flug, which also attracted attention to the Reichsluftfahrtministerium (Reich Aviation Ministry). They got the idea to build a bomber that could strike the United States from Germany. The Ministry gave Sänger a position in a research institute near Braunschweig and also built a liquid oxygen plant and a test stand for a 100 tonne thrust engine.
In 1936, Sänger started leading a rocket development team at Lüneburger Heide and gradually, he conceived a rocket-powered sled that would launch a bomber with its own rocket engines that would climb to the fringe of space and then skip along the upper atmosphere. The so-called Silbervogel covered the large distances in a series of suborbital hops.
When Eugen Sänger designed rocket motors which the space-plane would use, it had to generate about 1 meganewton of thrust. Back then, Sänger was one of the first to suggest using the rocket’s fuel as a way of cooling the engine, by circulating it around the rocket nozzle before burning it in the engine. In 1942, Eugen Sänger was entitled to work for the Deutsche Forschungsanstalt für Segelflug (German Gliding Research Institute) where he worked on ramjet-technology and the Skoda-Kauba Sk P.14 interceptor.
After the war ended, Sänger worked for the French government and in 1949 founded the Fédération Astronautique. In 1951, he became the first President of the International Astronautical Federation. Eugen Sänger returned to Germany in 1954 to research on jet propulsion in Stuttgart. In the 1960s, Sänger acted as a consultant for Junkers in designing a ramjet-powered space-plane that never left the drawing board. Further innovations that Eugen Sänger was involved in included the use of photons for interplanetary and interstellar spacecraft propulsion prefiguring the concept of laser propulsion and the solar sail.
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