Prof. Dr. Ernst Willi Messerschmid (born May 21, 1945) is a German physicist and former astronaut.Born in Reutlingen, Germany, Messerschmid finished the Technisches Gymnasium in Stuttgart in 1965. After two years of military service he studied physics at the University of Tübingen and Bonn, receiving diploma degree in 1972 and doctorate in 1976. From 1970 to 1975 he was also visiting scientist at the CERN in Geneva, working on proton beams in accelerators and plasmas.