Helmut Hölzer

Helmut Hölzer in Huntsville

Helmut Hölzer (born February 27, 1912 in Bad Liebenstein ; † August 19, 1996 in Huntsville (Alabama) ) was a German computer and rocket pioneer.

Life

Helmut Hölzer was born in Bad Liebenstein, Thuringia, in 1912. His parents were the businessman Bernhard Alexander August Hölzer (* 1880) and Emmy Selma Frida, b. Roth (* 1885). The marriage ended in divorce. His mother ran a pension there, and his father probably owned the Thuringian stone works in the immediate vicinity of his brother Bernhard's nursery. Helmut Hölzer went to primary school for three years and then to the pedagogy in his hometown. He attended secondary school in Bad Salzungen until Easter 1931. After graduating from high school in 1931, he worked for six months at the Meiningen Reichsbahn repair shop . From 1931 to 1939 he studied electrical engineering at the TH Darmstadt . From autumn 1935 to spring 1937 he worked as an assistant at the engineering school in Frankenhausen and from spring 1937 to May 1939 at the engineering school for aerospace engineering in Darmstadt under Franz Nikolaus Scheubel . He successfully passed the main diploma examination for electrical engineering in May 1939. Together with his teacher Alwin Walther , he developed a slide rule system in Darmstadt with an error of only 0.16%.

In 1935, as a glider pilot, he discovered that there was no measuring device for the ground speed. To this end, he wanted to integrate the accelerations and make the topic his study work. Mechanical integrators were built by Udo Knorr in 1914 and Vannevar Bush in 1923 . He was referred by Hans Busch to his main assistant Kurt Heinrich Debus , Ernst Hueter and Viktor Blaess , but they showed no interest in the problem of the integrator. So he limited himself to the theoretical investigation of the imitation of mathematical operations through electrical networks.

Work in Peenemünde

Memorial plaque in the Neu Pudagla Forestry Office

For a short time he worked in the laboratory for high frequency research of the Telefunken company in Berlin. In October 1939 there was a meeting with Ernst Steinhoff , Hermann Steuding and Wernher von Braun about guide beams for missiles. At the beginning of the Second World War he was conscripted and deployed to the Peenemünde Army Research Center . A gyro course control as an autopilot was planned for the rocket unit 4 . Since this is powerless against influences such as cross winds, it was his task to develop a superimposed radio remote control. Otto Heinrich Hirschler became his assistant . The teams for course control and remote control were organizationally separated.

Since the remote control showed instabilities and disturbances built up, he needed a real-time integrator and differentiator, which he wanted to implement with capacitors. Since direct current amplifiers were not yet fully developed and the drift could not be brought under control, he chose an alternating current amplifier using tube technology. The measured value was modulated onto the alternating voltage with a suppressed 500 Hz carrier. For modulation he used a ring modulator with semiconductors made of copper oxide .

Walter Häussermann had built a test stand and Josef Maria Boehm a vibrating table for electro-mechanical simulation. However, the servos for the thrusters turned out to be too slow. In addition to the angular velocity from the turning pointers , they also needed the angular acceleration. The complete course and remote control system was given the camouflage name Mixing Device , because the mixing of the various signals also took place there. Hans Henning Hosenthien and Otto Heinrich Hirschler built a second generation of the analog computer. Due to the bombing of Peenemünde, the 31-year-old had to save himself with his invention in the forester's house in New Pudagla . While he was further developing his device there, he met the daughter of the forester Muschwitz, whom he married only a year later.

Work in the USA

After the end of the war, his analog computer was brought to the USA as spoils of war in 1946 and used by the American army. In February 1946 he did his doctorate at the TH Darmstadt with his teacher Alwin Walther and Richard Vieweg with the thesis application of electrical networks for the solution of differential equations and for the stabilization of control processes and moved with several employees of the Peenemünde Army Research Center to the USA, where he worked under Wernher von Braun could continue to devote himself to rocket research. He worked at Fort Bliss and then at the Redstone Arsenal until the 1950s . He became Director of Computing at the Marshall Space Flight Center in 1960 , where he developed the remote control for the Apollo program's moon rockets .

His son Hans D. Hoelzer (∞ Elizabeth Livingston) also became an engineer. His granddaughters are Martha and Margaret Hoelzer .

Honors

• Extraordinary Medal of Merit from NASA.
• Copernicus Medal of the Man and Space Board of Trustees.

Publications

• 1946: Use of electrical networks to solve differential equations and to stabilize control processes , Darmstadt, dissertation dated February 11, 1946.

literature

• Michael J. Neufeld: The rocket and the realm. Wernher von Braun, Peenemünde and the beginning of the rocket age , Berlin 1999.
• James E. Tomayko, Helmut Hoelzer's Fully Electronic Analog Computer ; In: IEEE Annals of the History of Computing , Vol. 7, No. 3, pp. 227–240, July – Sept. 1985, doi: 10.1109 / MAHC.1985.10025

Web links

Commons : Helmut Hölzer  - Collection of images, videos and audio files

Individual evidence

1. ↑ http://www.heimatfreundebali.de/heimatgeschichte/villen/villa-perlet/
2. ↑ http://www.heimatfreundebali.de/heimatgeschichte/firmen/gärtnerei-bachmann/
3. ↑ http://www.heimatfreundebali.de/heimatgeschichte/schulen/volks-grundschule/
4. ↑ http://www.heimatfreundebali.de/heimatgeschichte/schulen/p%C3%A4dagogium-gymnasium/
5. ↑ Klaus Biener: Alwin Walther - Pioneer of practical mathematics. (PDF; 1.9 MB) In: RZ-Mitteilungen No. 18, August 1999. August 1999, pp. 60–62 , accessed on April 11, 2010 : “This slide rule (with a stick length of 25 cm) has the remarkable Accuracy of 1.6 ‰ and was designed jointly by A. Walther and his student Helmut Hoelzer. " 
6. ^ Ritter von Baeyer, Hoelzer: frame antenna. November 17, 1942, accessed on January 20, 2020 (click on "Load complete document" after calling up). 
7. ↑ Roosenstein, Hoelzer: arrangement for coupling an antenna. February 4, 1943, accessed on January 20, 2020 (click on "Load complete document" after calling up). 
8. ↑ Roosenstein, Hoelzer: Device for the artificial earthing of a high-frequency conductor . January 14, 1941, accessed on January 20, 2020 (click on "Load complete document" after calling up). 
9. ↑ Roosenstein, Hoelzer: Device for wave suppression on a high frequency conductor. January 14, 1941, accessed on January 20, 2020 (click on "Load complete document" after calling up). 
10. ↑ Helmut Hölzer in the Encyclopedia Astronautica , accessed on April 11, 2010 (English).
11. ^ Wolfgang Saxon: H. Otto Hirschler, 87, Aided Space Program. The New York Times, February 9, 2001, accessed April 11, 2010 . 
12. ^ Walter Häussermann in the Encyclopedia Astronautica, accessed on April 11, 2010 (English).
13. ↑ Josef Maria Boehm in the Encyclopedia Astronautica, accessed on April 11, 2010 (English).
14. ↑ Hans Henning Hosenthien in the Encyclopedia Astronautica, accessed on April 11, 2010 (English).
15. ↑ http://www.heimatfreundebali.de/heimatgeschichte/b%C3%BCrger/h%C3%B6lzer/
16. ↑ Joachim Fischer: What do analog computers and Simula-67 have to do with modern modeling languages? In: Computer Science: Current Issues in a Historical Context. Johann Christoph Freytag, Wolfgang Reisig, pp. 106–110 , accessed on April 11, 2010 .