Hermann Oberth

Hermann Julius Oberth was an Austro-Hungarian-born German physicist and rocket pioneer of Transylvanian Saxon descent. Oberth supported Nazi Germany's war effort and received the War Merit Cross in 1943.''''

Early life

Oberth was born into a Transylvanian Saxon family in Nagyszeben, Kingdom of Hungary ; and besides his native German, he was fluent in Hungarian and Romanian as well. At the age of 11, Oberth's interest in rocketry was sparked by the novels of Jules Verne, especially From the Earth to the Moon and Around the Moon. He was fond of reading them over and over until they were engraved in his memory. As a result, Oberth constructed his first model rocket as a school student at the age of 14. In his youthful experiments, he arrived independently at the concept of the multistage rocket. During this time, however, he lacked the resources to put his ideas into practice.
In 1912, Oberth began studying medicine in Munich, Germany, but after World War I broke out, he was drafted into the Imperial German Army, assigned to an infantry battalion, and sent to the Eastern Front against Russia. In 1915, Oberth was moved into a medical unit at a hospital in Segesvár, Transylvania, in Austria-Hungary. There he found the spare time to conduct a series of experiments concerning weightlessness, and later resumed his rocketry designs. By 1917, he showed designs of a missile using liquid propellant with a range of to Hermann von Stein, the Prussian Minister of War.
On 6 July 1918, Oberth married Mathilde Hummel, with whom he had four children. Among Oberth's children, one lost his life as a soldier during World War II. His daughter, Ilse, died on August 28, 1944, in an accidental explosion at the Redl-Zipf V-2 rocket engine test facility and liquid oxygen plant where she worked as a rocket technician.
In 1919, Oberth once again moved to Germany, this time to study physics, initially in Munich and later at the University of Göttingen.
In 1922, Oberth's proposed doctoral dissertation on rocket science was rejected as "utopian". However, professor Augustin Maior of the University of Cluj in Romania offered Oberth the opportunity to defend his original dissertation there in order to receive a doctorate. He did so successfully on 23 May 1923. He next had his 92-page work published privately in June 1923 as the somewhat controversial book, Die Rakete zu den Planetenräumen. By 1929, Oberth had expanded this work to a 429-page book titled Wege zur Raumschiffahrt. Oberth commented later that he made the deliberate choice not to write another doctoral dissertation. He wrote, "I refrained from writing another one, thinking to myself: Never mind, I will prove that I am able to become a greater scientist than some of you, even without the title of Doctor." Oberth criticized the German system of education, saying "Our educational system is like an automobile which has strong rear lights, brightly illuminating the past. But looking forward, things are barely discernible."
Oberth became in 1927 a member of the Verein für Raumschiffahrt – the "Spaceflight Society" – an amateur rocketry group that had taken great inspiration from his book, and Oberth acted as something of a mentor to the enthusiasts who joined the Society, which included persons such as Wernher von Braun, Rolf Engel, Rudolf Nebel or Paul Ehmayr. Oberth lacked the opportunities to work or to teach at the college or university level, as did many well-educated experts in the physical sciences and engineering in the time period of the 1920s through the 1930s – with the situation becoming much worse during the worldwide Great Depression that started in 1929. Therefore, from 1924 through 1938, Oberth supported himself and his family by teaching physics and mathematics at the Stephan Ludwig Roth High School in Mediaș, Romania.

Rocketry and spaceflight

During portions of 1928 and 1929, Oberth served as a scientific advisor in Berlin for the film Woman in the Moon, which was written by Thea von Harbou and directed and produced by Fritz Lang, in collaboration with the Universum Film AG company. The film was of enormous value in popularizing the ideas of rocketry and space exploration. One of Oberth's main assignments was to build and launch a rocket as a publicity event just before the film's premiere. He also designed the model of the Friede, the main rocket portrayed in the film.
On June 5, 1929, Oberth won the inaugural Prix REP-Hirsch from the French Astronomical Society. This honor recognized his significant contributions to the field of astronautics and interplanetary travel, specifically highlighted in his book Wege zur Raumschiffahrt. The book, an expanded version of Die Rakete zu den Planetenräumen, secured his position as a prominent figure in the field. The volume is dedicated to Lang and von Harbou.
Oberth's student Max Valier joined forces with Fritz von Opel to create the world's first large-scale experimental rocket program Opel-RAK, leading to speed records for ground and rail vehicles and the world's first rocket plane. Opel RAK.1, a purpose-built design by Julius Hatry, was demonstrated to the public and world media on September 30, 1929, piloted by von Opel. Valier's and von Opel's demonstrations had a strong and long-lasting impact on later spaceflight pioneers, in particular on another of Oberth's students, Wernher von Braun.
Shortly after the Opel RAK team's successful liquid-fuel rocket launches of April 10 and 12, 1929 by Friedrich Wilhelm Sander at Opel Rennbahn in Rüsselsheim, Oberth conducted in the autumn of 1929 a static firing of his first liquid-fueled rocket motor, which he named the Kegeldüse. The engine was built by Klaus Riedel in a workshop space provided by the Reich Institution of Chemical Technology, and although it lacked a cooling system, it did run briefly. He was helped in this experiment by an 18-year-old student Wernher von Braun, who would later become a giant in both German and American rocket engineering from the 1940s onward, culminating with the gigantic Saturn V rockets that made it possible for man to land on the Moon in 1969 and in several following years. Indeed, Von Braun said of him:

Basic research and technical drafts

The rocket in spaceflight

In 1923, Oberth's book The Rocket to the Planetary Spaces was published. This publication is generally regarded as a kind of initial spark for rocket and space travel enthusiasm in Germany. Many later rocket engineers were inspired by his precise and comprehensive theoretical considerations and his bold conclusions. The work sparked heated debates, known at the time as the Battle of the Many Formulas. The second edition appeared in 1925, and it was also sold out after a short time.
In his book, Oberth puts forward the following theses:

Premise 1: With the current level of science and technology, the construction of machines that can fly higher than the Earth's atmosphere is likely.
Premise 2: With further refinement, these machines can reach such speeds that they do not have to fall back to the Earth's surface and are even able to leave the Earth's sphere of attraction.
Premise 3: Such machines can be built in such a way that people can ride up with them.
Premise 4: Under certain economic conditions, the construction of such machines can be worthwhile. Such conditions can occur in a few decades.

With the launch of Sputnik and the flight of Yuri Gagarin into space, these ideas, which were still completely utopian at the beginning of the 1920s, became a reality less than four decades later.
Marsha Freeman writes, "The rockets were only a means to an end, his goal was space travel." Oberth thought of interplanetary space travel, of a multiplanetary humanity. In his first book in 1923 he gives the first "outlook":
He goes into more detail on physical and physical-chemical, as well as physiological experiments in weightless space, on the space telescope, research into the solar corona, the space station for Earth observation and the space mirror in Earth orbit for influencing the weather
The third, greatly expanded edition of his first book was published by Oberth in 1929 with the new title Ways to Spaceflight. In the years that followed, the book became the standard work for space exploration and rocket technology and was called the "Bible of scientific astronautics" by the French aviation and rocket pioneer Robert Esnault-Pelterie.
In this book, Oberth describes possible uses of his two-stage rocket, among other things on pages 285 to 333 the crewed space flight including space suit for external use, the space telescope for Earth observation and the duration of interplanetary flights, on pages 333 to 350 his ideas and the theoretical basis for space stations in near Earth orbit from 700 to 1200 km above the ground for Earth and weather observation and as a starting point for flights to the Moon and to the planets, on pages 336 to 351 he explains the construction and function of the space mirror he invented in 1923 with 100 bis 300 km in diameter in Earth orbit, with which, among other things, the weather is to be influenced in a targeted regional manner or the solar radiation is to be weakened in a targeted regional manner.
On pages 350 to 386 in the chapter "Journeys to Strange Worlds", Hermann Oberth presents his scientific considerations and calculations for flights to the Moon, to asteroids, to Mars, to Venus, to Mercury and to comets.

Space Mirror

In 1923, Oberth initially outlined the concept of his space mirrors in his book Die Rakete zu den Planetenräumen. These mirrors, with diameters ranging from 100 to 300 km, were envisioned to be composed of a grid network consisting of individually adjustable facets.
Oberth's concept of space mirrors in orbit around the Earth serves the purpose of focusing sunlight on specific regions of the planet's surface or redirecting it into space. This approach differs from creating shaded areas at the Lagrange point between the Earth and the Sun, as it does not involve diminishing solar radiation across the entire exposed surface. According to Oberth, these colossal orbital mirrors possess the potential to illuminate individual cities, safeguard against natural disasters, manipulate weather patterns and climate, and even create additional living space for billions of people. He places significant emphasis on their capacity to influence the trajectories of barometric high and low-pressure areas. However, it is important to acknowledge that the implementation of such climate engineering interventions, including space mirrors, requires further extensive research before their practical applicability can be fully realized.
Further publications followed in which he took into account the technical progress achieved up to that point: Ways to Spaceflight, Menschen im Weltraum. Neue Projekte für Raketen-und Raumfahrt, and Der Weltraumspiegel.
To optimize costs, Oberth's concept proposes the utilization of lunar minerals for producing components on the Moon. The Moon's lower gravitational pull necessitates less energy for launching these components into lunar orbit. Additionally, the Earth's atmosphere is spared the burden of numerous rocket launches. The envisioned process involves launching the components from the lunar surface into lunar orbit using an electromagnetic lunar slingshot, subsequently "stacking" them at a 60° libration point. These components could then be transported into orbit via electric spaceships, designed by Oberth with minimal recoil. Once in orbit, the components would be assembled into mirrors with diameters ranging from 100 to 300 km. Oberth's estimate in 1978 suggested that the realization of this concept could occur between 2018 and 2038.
Oberth emphasized that these mirrors could potentially serve as weapons. Given this aspect, coupled with the complexity of the project, the realization of these mirrors would only be feasible as a peace initiative undertaken by humanity.
In 2023, the space mirror devised by Oberth is categorized within the field of Climate Engineering, specifically under Solar Radiation Management as a subset of Space-Mirrors. The associated risks of these deliberate interventions in weather and climate are also examined and deliberated upon within this classification.