Eugen Sänger
Encyclopedia
Eugen Sänger was an Austrian-German aerospace
engineer best known for his contributions to lifting body
and ramjet
technology.
(flooded by the Preßnitz
dam in 1974) in Bohemia
, at that time part of the Austro-Hungarian Empire
. He studied civil engineering
at the Technical Universities of Graz
and Vienna
. As a student, he came in contact with Hermann Oberth
's book Die Rakete zu den Planetenräumen ("By Rocket into Planetary Space"), which inspired him to change from studying civil engineering to aeronautics
. He also joined Germany's amateur rocket movement, the Verein für Raumschiffahrt
(VfR - "Society for Space Travel") which was centered on Oberth.
Sänger made rocket-powered flight the subject of his thesis
, but it was rejected by the university as too fanciful. He was allowed to graduate when he submitted a far more mundane paper on the statics of wing trusses. Sänger would later publish his rejected thesis under the title Raketenflugtechnik ("Rocket Flight Engineering") in 1933. In 1935 and 1936, he published articles on rocket
-powered flight for the Austrian journal Flug ("Flying.") These attracted the attention of the Reichsluftfahrtministerium (RLM, or "Reich Aviation Ministry") which saw Sänger's ideas as a potential way to accomplish the goal of building a bomber that could strike the United States from Germany (the Amerika Bomber
project). The RLM gave him a research institute near Braunschweig
and also built a liquid oxygen
plant and a test stand
for a 100 metric ton thrust
engine. At the time, Sänger's hiring was opposed by Wernher von Braun
, who felt that his own work was being duplicated and may have seen the Austrian and his work as a threat to his own dominance of the field.
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 - not actually entering orbit
, but able to cover vast distances in a series of sub-orbital hops. This remarkable design was called the Silbervogel ("Silverbird") and would have relied on its fuselage
creating lift (as a lifting body
) to carry it along its sub-orbital path. Sänger was assisted in this design by mathematician
Irene Bredt
, whom he married. Sänger also designed the rocket motors that the space-plane would use, which would need to generate 1 meganewton (225,000 lbf) of thrust
. In this design, he 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.
By 1942, the Reich Air Ministry
canceled this project along with other more ambitious and theoretical designs in favour of concentrating on proven technologies. Sänger was sent to work for the Deutsche Forschungsanstalt für Segelflug
(DFS, or "German Gliding Research Institute"). There he did important work on ramjet
technology until the end of World War II
.
and in 1949 founded the Fédération Astronautique. Whilst in France, he was the subject of a botched attempt by Soviet
agents to win him over. Joseph Stalin
had become intrigued by reports of the Silbervogel design and sent his son, Vasily
, and scientist Grigori Tokaty
to convince him to come to the Soviet Union, but they failed to do so. It has also been reported that Stalin instructed the NKVD
to kidnap him.
In 1951, he became the first President of the International Astronautical Federation
.
By 1954, Sänger had returned to Germany and three years later was directing a jet propulsion
research institute in Stuttgart
. Between 1961 and 1963 he acted as a consultant for Junkers in designing a ramjet-powered space-plane that never left the drawing board. Sänger's other theoretical innovations during this period were proposing means of using photon
s for interplanetary and interstellar spacecraft propulsion, including the solar sail
.
He died in Berlin. The Sänger's grave is located on the cemetery "Alter Friedhof" in Stuttgart-Vaihingen.
His work on the Silbervogel would prove important to the X-15
, X-20 Dyna-Soar
, and ultimately Space Shuttle program
s.
Aerospace
Aerospace comprises the atmosphere of Earth and surrounding space. Typically the term is used to refer to the industry that researches, designs, manufactures, operates, and maintains vehicles moving through air and space...
engineer best known for his contributions to lifting body
Lifting body
A lifting body is a fixed-wing aircraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage with little or no conventional wing...
and ramjet
Ramjet
A ramjet, sometimes referred to as a stovepipe jet, or an athodyd, is a form of airbreathing jet engine using the engine's forward motion to compress incoming air, without a rotary compressor. Ramjets cannot produce thrust at zero airspeed and thus cannot move an aircraft from a standstill...
technology.
Early career
Sänger was born in the former mining town of Preßnitz (Přísečnice), ChomutovChomutov District
Chomutov District is one of seven districts located within the Ústí nad Labem Region in the Czech Republic...
(flooded by the Preßnitz
Preßnitz
The Preßnitz is a right-hand tributary of the River Zschopau in the state of Saxony in eastern Germany and in the Czech Republic. It rises in the Bohemian Ore Mountains near Horní Halže, northwest of the mining town of Měděnec.- Course :...
dam in 1974) in Bohemia
Bohemia
Bohemia is a historical region in central Europe, occupying the western two-thirds of the traditional Czech Lands. It is located in the contemporary Czech Republic with its capital in Prague...
, at that time part of the Austro-Hungarian Empire
Austria-Hungary
Austria-Hungary , more formally known as the Kingdoms and Lands Represented in the Imperial Council and the Lands of the Holy Hungarian Crown of Saint Stephen, was a constitutional monarchic union between the crowns of the Austrian Empire and the Kingdom of Hungary in...
. He studied civil engineering
Civil engineering
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including works like roads, bridges, canals, dams, and buildings...
at the Technical Universities of Graz
Graz University of Technology
The Graz University of Technology is the second largest university in Styria, Austria, after the University of Graz. Austria has three universities of technology – in Graz, in Leoben, and in Vienna. The Graz University of Technology was founded in 1811 by Archduke John of Austria. TUG, as the...
and Vienna
Vienna University of Technology
Vienna University of Technology is one of the major universities in Vienna, the capital of Austria. Founded in 1815 as the "Imperial-Royal Polytechnic Institute" , it currently has about 26,200 students , 8 faculties and about 4,000 staff members...
. As a student, he came in contact with Hermann Oberth
Hermann Oberth
Hermann Julius Oberth was an Austro-Hungarian-born German physicist and engineer. He is considered one of the founding fathers of rocketry and astronautics.- Early life :...
's book Die Rakete zu den Planetenräumen ("By Rocket into Planetary Space"), which inspired him to change from studying civil engineering to aeronautics
Aeronautics
Aeronautics is the science involved with the study, design, and manufacturing of airflight-capable machines, or the techniques of operating aircraft and rocketry within the atmosphere...
. He also joined Germany's amateur rocket movement, the Verein für Raumschiffahrt
Verein für Raumschiffahrt
The Verein für Raumschiffahrt was a German amateur rocket association prior to World War II that included members outside of Germany...
(VfR - "Society for Space Travel") which was centered on Oberth.
Sänger made rocket-powered flight the subject of his thesis
Thesis
A dissertation or thesis is a document submitted in support of candidature for an academic degree or professional qualification presenting the author's research and findings...
, but it was rejected by the university as too fanciful. He was allowed to graduate when he submitted a far more mundane paper on the statics of wing trusses. Sänger would later publish his rejected thesis under the title Raketenflugtechnik ("Rocket Flight Engineering") in 1933. In 1935 and 1936, he published articles on rocket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...
-powered flight for the Austrian journal Flug ("Flying.") These attracted the attention of the Reichsluftfahrtministerium (RLM, or "Reich Aviation Ministry") which saw Sänger's ideas as a potential way to accomplish the goal of building a bomber that could strike the United States from Germany (the Amerika Bomber
Amerika Bomber
The Amerika-Bomber project was an initiative of the Reichsluftfahrtministerium, the Nazi Germany Air Ministry, to obtain a long-range strategic bomber for the Luftwaffe that would be capable of striking the continental United States from Germany, a range of about 5,800 km...
project). The RLM gave him a research institute near Braunschweig
Braunschweig
Braunschweig , is a city of 247,400 people, located in the federal-state of Lower Saxony, Germany. It is located north of the Harz mountains at the farthest navigable point of the Oker river, which connects to the North Sea via the rivers Aller and Weser....
and also built a liquid oxygen
Liquid oxygen
Liquid oxygen — abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries — is one of the physical forms of elemental oxygen.-Physical properties:...
plant and a test stand
Rocket engine test facility
A rocket engine test facility is a location where rocket engines may be tested on the ground, under controlled conditions. A ground test program is generally required before the engine is certified for flight...
for a 100 metric ton thrust
Thrust
Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction the accelerated mass will cause a force of equal magnitude but opposite direction on that system....
engine. At the time, Sänger's hiring was opposed by Wernher von Braun
Wernher von Braun
Wernher Magnus Maximilian, Freiherr von Braun was a German rocket scientist, aerospace engineer, space architect, and one of the leading figures in the development of rocket technology in Nazi Germany during World War II and in the United States after that.A former member of the Nazi party,...
, who felt that his own work was being duplicated and may have seen the Austrian and his work as a threat to his own dominance of the field.
Sub-orbital bomber concept
Sänger agreed to lead a rocket development team in the Lüneburger Heide region in 1936. He gradually conceived a rocket-powered sledSled
A sled, sledge, or sleigh is a land vehicle with a smooth underside or possessing a separate body supported by two or more smooth, relatively narrow, longitudinal runners that travels by sliding across a surface. Most sleds are used on surfaces with low friction, such as snow or ice. In some cases,...
that would launch a bomber
Bomber
A bomber is a military aircraft designed to attack ground and sea targets, by dropping bombs on them, or – in recent years – by launching cruise missiles at them.-Classifications of bombers:...
with its own rocket engines that would climb to the fringe of space and then skip along the upper atmosphere - not actually entering orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
, but able to cover vast distances in a series of sub-orbital hops. This remarkable design was called the Silbervogel ("Silverbird") and would have relied on its fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
creating lift (as a lifting body
Lifting body
A lifting body is a fixed-wing aircraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage with little or no conventional wing...
) to carry it along its sub-orbital path. Sänger was assisted in this design by mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
Irene Bredt
Irene Bredt
Irene Bredt was a German engineer, mathematician and physicist. She is co-credited with the design of a proposed intercontinental spaceplane/bomber prior to and during World War II....
, whom he married. Sänger also designed the rocket motors that the space-plane would use, which would need to generate 1 meganewton (225,000 lbf) of thrust
Thrust
Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction the accelerated mass will cause a force of equal magnitude but opposite direction on that system....
. In this design, he 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.
By 1942, the Reich Air Ministry
Reich Air Ministry
thumb|300px|The Ministry of Aviation, December 1938The Ministry of Aviation was a government department during the period of Nazi Germany...
canceled this project along with other more ambitious and theoretical designs in favour of concentrating on proven technologies. Sänger was sent to work for the Deutsche Forschungsanstalt für Segelflug
Deutsche Forschungsanstalt für Segelflug
The Deutsche Forschungsanstalt für Segelflug, or DFS was formed in 1933 to centralise all gliding activity in Germany...
(DFS, or "German Gliding Research Institute"). There he did important work on ramjet
Ramjet
A ramjet, sometimes referred to as a stovepipe jet, or an athodyd, is a form of airbreathing jet engine using the engine's forward motion to compress incoming air, without a rotary compressor. Ramjets cannot produce thrust at zero airspeed and thus cannot move an aircraft from a standstill...
technology until the end of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
Postwar
After the war ended, Sänger worked for the French governmentGovernment of France
The government of the French Republic is a semi-presidential system determined by the French Constitution of the fifth Republic. The nation declares itself to be an "indivisible, secular, democratic, and social Republic"...
and in 1949 founded the Fédération Astronautique. Whilst in France, he was the subject of a botched attempt by Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
agents to win him over. Joseph Stalin
Joseph Stalin
Joseph Vissarionovich Stalin was the Premier of the Soviet Union from 6 May 1941 to 5 March 1953. He was among the Bolshevik revolutionaries who brought about the October Revolution and had held the position of first General Secretary of the Communist Party of the Soviet Union's Central Committee...
had become intrigued by reports of the Silbervogel design and sent his son, Vasily
Vasily Dzhugashvili
Vasily Iosifovich Dzhugashvili , known also as Vasily Stalin , , was the son of Joseph Stalin and his second wife, Nadezhda Alliluyeva....
, and scientist Grigori Tokaty
Grigori Tokaty
Dr Grigori Tokaty was a rocket scientist and long-standing critic of Stalin's USSR. During World War II he served as Head of Aeronautics Laboratory, Zhukovsky Academy 1938-41...
to convince him to come to the Soviet Union, but they failed to do so. It has also been reported that Stalin instructed the NKVD
NKVD
The People's Commissariat for Internal Affairs was the public and secret police organization of the Soviet Union that directly executed the rule of power of the Soviets, including political repression, during the era of Joseph Stalin....
to kidnap him.
In 1951, he became the first President of the International Astronautical Federation
International Astronautical Federation
International Astronautical Federation , the world's foremost space advocacy organisation, is based in Paris. It was founded in 1951 as a non-governmental organization. It has 206 members from 58 countries across the world. They are drawn from space agencies, industry, professional associations,...
.
By 1954, Sänger had returned to Germany and three years later was directing a jet propulsion
Jet propulsion
Jet propulsion is motion produced by passing a jet of fluid in the opposite direction to the direction of motion. By conservation of momentum, the moving body is propelled in the opposite direction to the jet....
research institute in Stuttgart
Stuttgart
Stuttgart is the capital of the state of Baden-Württemberg in southern Germany. The sixth-largest city in Germany, Stuttgart has a population of 600,038 while the metropolitan area has a population of 5.3 million ....
. Between 1961 and 1963 he acted as a consultant for Junkers in designing a ramjet-powered space-plane that never left the drawing board. Sänger's other theoretical innovations during this period were proposing means of using photon
Photon
In physics, a photon is an elementary particle, the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic radiation. It is also the force carrier for the electromagnetic force...
s for interplanetary and interstellar spacecraft propulsion, including the solar sail
Solar sail
Solar sails are a form of spacecraft propulsion using the radiation pressure of light from a star or laser to push enormous ultra-thin mirrors to high speeds....
.
He died in Berlin. The Sänger's grave is located on the cemetery "Alter Friedhof" in Stuttgart-Vaihingen.
His work on the Silbervogel would prove important to the X-15
North American X-15
The North American X-15 rocket-powered aircraft/spaceplane was part of the X-series of experimental aircraft, initiated with the Bell X-1, that were made for the USAAF/USAF, NACA/NASA, and the USN. The X-15 set speed and altitude records in the early 1960s, reaching the edge of outer space and...
, X-20 Dyna-Soar
X-20 Dyna-Soar
The X-20 Dyna-Soar was a United States Air Force program to develop a spaceplane that could be used for a variety of military missions, including reconnaissance, bombing, space rescue, satellite maintenance, and sabotage of enemy satellites...
, and ultimately Space Shuttle program
Space Shuttle program
NASA's Space Shuttle program, officially called Space Transportation System , was the United States government's manned launch vehicle program from 1981 to 2011...
s.
Books and technical reports
- Saenger, Hartmut E and Szames, Alexandre D, From the Silverbird to Interstellar Voyages, IAC-03-IAA.2.4.a.07.
See also
- Silbervogel
- Keldysh bomberKeldysh bomberThe Keldysh bomber was a Soviet design for a rocket-powered sub-orbital bomber aircraft which drew heavily upon work carried out by Eugen Sänger and Irene Bredt for the German Silbervogel project.- Development :...
- Spacecraft propulsionSpacecraft propulsionSpacecraft propulsion is any method used to accelerate spacecraft and artificial satellites. There are many different methods. Each method has drawbacks and advantages, and spacecraft propulsion is an active area of research. However, most spacecraft today are propelled by forcing a gas from the...