Ernst Willi Messerschmid (born May 21, 1945) is a German physicist and former astronaut. From 1978 to 1982, he worked at the DFVLR (the precursor of the DLR) in the Institute of Communications Technology in Oberpfaffenhofen on space-borne communications. In 1983, he was selected as one of the astronauts for the first German Spacelab mission D-1. He flew as payload specialist on STS-61-A in 1985, spending over 168 hours in space.