Paths to space travel

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Ways to Space Travel by Hermann Oberth was published in 1929 by the Oldenbourg Verlag in Munich and was long considered a standard work in rocket technology. It was - with a new title and completely revised - the 3rd edition of Oberth's first book The Rocket for Planetary Spaces (1923).

In this work, Oberth implements “the dream of space travel, which mankind has cherished for centuries, into the language of formulas and construction drafts”. Even after the introduction of powerful electronic calculating machines that deliver numerically more accurate results, the work and its formulas were used in research, development and teaching in space technology because “one can read from the formulas what really matters, how things are connected and how to find the best middle ground between all of them ”.

content

The work is divided into four parts: The first part deals in general terms with the principles of the recoil drive and its operation in space. His starting point are four assumptions that were not verifiable at the time and therefore controversial:

  1. It is possible to build machines that can rise higher than the atmosphere can reach.
  2. With further perfection these machines are able to reach such speeds that they - left to themselves in the etheric space - do not have to fall back on the earth's surface and are even able to leave the area of ​​attraction of the earth.
  3. Such machines can be built in such a way that people (probably without any health problems) can go up with them.
  4. Under the current conditions, building such machines will be worthwhile.
Design of a two-stage liquid rocket

In the second part ( physical-technical questions ) and third part ( constructive questions ) Oberth describes in detail his principles of rocket propulsion with liquid fuels. He often simplified the mathematical derivations and formulas considerably by using approximate values ​​for certain quantities that were easy to handle mathematically. Where the values ​​for the formula parameters were still uncertain, Oberth always calculated under unfavorable assumptions in order to be sure that his rockets can achieve the required performance. Oberth was the first to arrive at the three-stage rocket by designing a 100-tonne space rocket and calculated the optimal ratio between the various stages. In the fourth part he discusses the possible uses of his rockets, first of all the use of the rocket nozzle (for liquid fuels) on earth and in the rocket plane. Then he calculates and describes rockets that not only rise, but then - similar to the later space shuttle - can also return to Earth. Calculations and designs for space stations follow. He also designed numerous technical uses for the stations that would later become reality. Here are the most important ones: Global communication by means of satellites that receive and send signals, observation of the earth's surface, especially that of the unexplored countries, support for maritime navigation (by warning of icebergs), observation of meteorological data for weather forecasting, the space station as a stopover and fuel depot for transport to other planets, and solar sails to stabilize and propel satellites. In his foresight he also develops concepts for energy generation in space for use on earth by means of mirrors or electric waves ( microwaves ). This concept was taken up again in the USA from 1968 in feasibility studies under the name Solar Power Satellite (SPS) and has since been viewed as technically feasible in principle. Finally, in his book, Hermann Oberth discusses the requirements and technical possibilities for travel to other world bodies (moon, asteroids, Mars, Venus, etc.), with an emphasis on the use of an electric spaceship . The technology to be used here is known and tested today as the ion drive .

expenditure

The first edition appeared in 1923 with the title The rocket to the planetary spaces . The work sparked heated discussions, then known as the battle of many formulas . In 1925 the second edition appeared, which was sold out after a short time. The third extended edition appeared in 1929 with the new title Paths to Space Travel . In the following years the book became the standard work of space research and rocket technology. In 1960 the book was reissued under the original title The rocket for planetary spaces. In 1974 the new edition of Paths to Space was published by Kriterion Verlag, Bucharest, with a foreword by Elie Carafoli and updated comments by the author.

Appreciation

The former student of Oberth, Wernher von Braun , wrote in 1974: "Hermann Oberth was the first to use the slide rule in connection with the idea of ​​a real space trip and to submit numerically worked out concepts and construction drafts."

Individual evidence

  1. ^ Elie Carafoli, (1974), Professor of Aero-Gas Dynamics at the Bucharest Polytechnic Institute and formerly Director of the Institut de Mécanique des Fluides “Traian Vuia” in Bucharest, holder of the Carl Friedrich Gauß Medal , Past President of International Astronautical Federation (IAF)
  2. ^ Hermann Oberth in the foreword to the third edition
  3. ↑ Oberth himself later wrote in a footnote to a reprint (Kriterion Verlag, Bucharest, 1974) that at that time people still spoke of the world ether , which was believed to be a gas that, among other things, should also be the carrier of light waves.
  4. ^ PE Glaser et al .: Solar Power Satellites - A Space Energy System for Earh. Wiley-Praxis Verlag, The White House, Chichester (UK) 1998, ISBN 0-471-96817-X .