Question: What field of work do both Gerhard Thiele and Léopold Eyharts have in common?

Context paragraphs:
Gerhard Marcks House: The Gerhard Marcks Museum or Gerhard Marcks House (German: "Gerhard Marcks Haus" ) is a museum in Bremen, Germany, inspired by the work of the sculptor and graphic artist Gerhard Marcks.  The museum exhibits contemporary sculpture, including the work of Marcks.

Léopold Eyharts: Léopold Eyharts (born April 28, 1957) is a Brigadier General in the French Air Force, an engineer and ESA astronaut.

Richter 858: Richter 858 is an album by Bill Frisell consisting of improvised music inspired by the paintings of German artist Gerhard Richter.  The album features Frisell, Eyvind Kang, Jenny Scheinman and Hank Roberts.  "Richter 858" was originally released as part of a limited-edition volume of Gerhard Richter's paintings which also contained poetry and essays by Dave Hickey and Klaus Kertess inspired by the artist's work.  The album was rereleased in 2005 on the Songlines label with a CD-ROM with MP3 music to accompany a slide show of the paintings, which are reproduced in an accompanying booklet.

Gerhard Neumann Museum: The Gerhard Neumann Museum is an aviation museum located in the German village of Niederalteich in Bavaria.  The museum chronicles the work of German aero engine designer, Gerhard Neumann, in particular the General Electric J79 turbojet and Lockheed F-104 Starfighter which this engine powered.  Many aerospace exhibits are on display including fixed-wing aircraft and aircraft engines.

Gerhard Thiele: Dr. Gerhard Paul Julius Thiele (born September 2, 1953) is a German physicist and a former ESA astronaut.

Johannes Thiele (zoologist): Johannes Thiele, full name Karl Hermann Johannes Thiele (1 October 1860 – 5 August 1935) was a German zoologist specialized in malacology.  His "Handbuch der systematischen Weichtierkunde" (English edition published by the Smithsonian under the title "Handbook of Systematic Malacology") is a standard work.  From 1904 until his retirement in 1925 he was the curator of the malacological collection at the Museum für Naturkunde (Museum of Natural History) in Berlin.

V. G. Braun-Dusemond: Valentin Gerhard Braun-Dusemond, born Gerhard Braun, (1919 – 1998), was a German painter and art dealer.  He lived and worked in several different countries, including East Africa and Malta, and his work embraced both Abstract Expressionist and Impressionist styles.

Begin Again (Nutshell album): Begin Again is the title of the third album by the Christian trio Nutshell.  Its title refers to the fact that previous members Pam Thiele and Heather Barlowe had left the group, to be replaced by Annie McCaig and Mo McCafferty.  As ever, the group's output was based on Paul Field's songwriting talents.

Richard H. Small: Richard H. Small (born 1935) is an American scientist, who has worked mainly in the field of electroacoustics.  He is known for the commonly used Thiele/Small parameters for loudspeaker enclosure design, which are named after Small and his colleague Neville Thiele.

The Girl and the Boy: The Girl and the Boy (French:La fille et le garçon) is a 1931 comedy film directed by Roger Le Bon and Wilhelm Thiele and starring Lilian Harvey, Henri Garat and Lucien Baroux.  It was made by the major studio UFA as the French-language version of "Two Hearts Beat as One", which also starred Harvey.  Such multiple-language versions were common in the early years of sound before dubbing became more widespread.

Supporting paragraphs: Gerhard Thiele Léopold Eyharts
Answer: ESA astronaut