Hans Jürgen Kärcher

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Hans Jürgen Kärcher

Hans Jürgen Kärcher (born May 11, 1941 in Offenbach am Main ) is a German systems engineer and is known worldwide by astronomers as a leading telescope designer. He sees himself as a pupil of the Gustavsburg School of Steel Construction

Life

Born in Offenbach and raised in Frankfurt-Fechenheim , initially studied mechanical engineering at the TH Darmstadt , then switched, under the influence of the lectures of Kurt Klöppel (1901–1985), to the then faculty of mathematics / physics with a focus on mathematics, mechanics, statics and steel construction, and pursued his tendencies to combine engineering with practical mathematics. A student project at Klöppel / Uhlmann, which was published in 1968 in “Stahlbau” under the title “A convergence improvement of the approximate load-bearing capacity calculation of frames” , was his first scientific publication. After his diploma in 1968, he worked as a research assistant at the chair for lightweight construction with Johannes Wissmann (1928–1999), in the early days of the large batch computers , with the introduction of finite elements into engineering. In 1973, the TH Darmstadt worked with of the dissertation " The finite element method based on continuum mechanics with an application of two hybrid element models to the disk calculation " for Dr.-Ing. PhD. He published the results of his dissertation in 1975 in the "International Journal for Numerical Methods in Engineering" .

From 1974 to 1986 Hans J. Kärcher worked under Winfried Schönbach (1931–2004), first as structural engineer, then as project manager and systems engineer at the MAN plant in Gustavsburg , where he first worked with parabolic antennas and radio telescopes. The traditional Gustavsburg steel structure was closed in 1986 as a result of the influence of globalization, and the remaining product groups - communication antennas and telescopes, bridge devices and theater construction - were assigned to MAN GHH ( Gutehoffnungshütte ) in Oberhausen Sterkrade, from 1997 to MAN Technologie AG and from 2005 to MT Aerospace in Augsburg, and Hans J. Kärcher took over the engineering department.

First SOFIA flight on April 26, 2007
The telescope in the fuselage of the aircraft

One of the highlights of the Mainz telescope team is the large millimeter wave radio telescope LMT (reflector diameter 50 m) completed in 2006 on Cerro la Negra, a 4600 m high secondary peak of Orizaba , the highest mountain in Mexico at 5636 m, via the Hans J. Kärcher 2003 and reported in 2006 in "Stahlbau" . He published an overview of radio telescopes in the steel construction calendar 2004 and 2009 in the September issue of " Steel Construction ".

Kärcher describes the mounting of the 2.7 m telescope of the Stratospheric Observatory for Infrared Astronomy (SOFIA) as the finest structural mechanics . The telescope developed by MT Mechatronics GmbH, a 100% subsidiary of MT Aerospace, together with a consortium partner for the German Aerospace Center (DLR) and the US space agency NASA is integrated into a modified Boeing 747 SP since November 30, 2010, astronomical observations in the infrared and submillimeter wavelength range have been carried out largely above the disturbing terrestrial air envelope; it is used to research the development of galaxies as well as stars and solar systems from interstellar clouds of molecules and dust. Kärcher was significantly involved in this ambitious SOFIA project from the start and published many articles about it in the proceedings of SPIE , the "International Society for Optics and Photonics", the international forum for telescope technology.

Although it was retired in 2006, Kärcher is still involved in the planning and development of new telescope projects. One of them is the Daniel K. Inouye Solar Telescope , which was completed in 2019 and was initially called the Advanced Technology Solar Telescope (ATST). He developed the mount together with colleagues from MT Mechatronics and a US partner company.

Works

  • Kärcher, HJ: The steel construction of the EISCAT VHF cylindrical parabolic antenna in Tromsö, Norway . In: Stahlbau 49 (1980), H. 9, pp. 269–275.
  • Kärcher, HJ: The large millimeter-wave telescope on Cerro la Negra in Mexico . In: Stahlbau 72 (2003), no. 11, pp. 759–766.
  • Kärcher, HJ: Radio telescopes . In: Stahlbau-Kalender 2004, ed. v. Ulrike Kuhlmann, pp. 633-702. Berlin: Ernst & Son 2004.
  • Kärcher, HJ: Big Lift for a millimeter-wave telescope in Mexico . In: Stahlbau 75 (2006), no. 3, pp. 237–238.
  • Kärcher, HJ: Large telescopes and bridge construction . In: Stahlbau 77 (2008), no. 8, pp. 566-574.
  • Kärcher, HJ: Antennas and telescopes . In: Of ideas and successes . 40 years of MAN TECHNOLOGIE, ed. v. Hans-Georg Hansen u. Horst Rauck. Dasing: Paartal-Verlag 2008, pp. 321–328, ISBN 978-3-00-025030-9 .
  • Kärcher, HJ: Telescope structures worldwide . Steel Construction - Design and Research 2 (2009), H. 3, pp. 149-160.
  • Kärcher, HJ, Li, Hui, Nan, R .: The steel structure of the 500 m radio telescope FAST . Stahlbau 85 (2016), no. 6, pp. 375–379.
  • Baars, JMM, Kärcher, HJ: Radio Telescope Reflectors . Berlin: Springer-Verlag 2018, ISBN 978-3-319-65148-4 .

literature

  • Karl-Eugen Kurrer : Hans Jürgen Kärcher 70 years . In: Stahlbau 80 (2011), no. 9, p. 693.
  • Thinking in terms of forces is essential for good design work - not just for telescopes . In: Stahlbau 85 (2016), no. 5, pp. 368–372 (Burkhard Talebitari interviewed Hans Jürgen Kärcher).

Web links

Commons : Stratospheric Observatory for Infrared Astronomy  - Collection of images, videos and audio files

Individual evidence

  1. ↑ Personal information from HJKärcher from January 18, 2018
  2. ^ Engineer Hans Jürgen Kärcher is involved in astronomy projects worldwide. Karbener Zeitung, June 5, 2008, accessed on January 16, 2018 .
  3. ↑ MT mechatronics. (No longer available online.) Archived from the original on January 13, 2018 ; accessed on January 16, 2018 .
  4. ↑ SOFIA - The flying infrared observatory. Retrieved January 16, 2018 .
  5. ^ Richard Moss: World's biggest solar telescope set for 2019 completion in Hawaii. February 16, 2015, accessed January 16, 2018 .
personal data
SURNAME Kärcher, Hans Jürgen
BRIEF DESCRIPTION German systems engineer
DATE OF BIRTH May 11, 1941
PLACE OF BIRTH Offenbach am Main