Walter was born in Iserlohn. After finishing secondary school there and two years in the Bundeswehr, he studied physics at the University of Cologne. In 1980, he was awarded a diploma degree, and five years later a doctorate, both in the field of solid-state physics.
After his spaceflight he worked for another four years at DLR, managing a space imaging database project. When the German astronaut team was merged into a European Space Agency, he did not transfer, but resigned to work at IBM Germany.
In 2003, he became full professor at the Technische Universität München (Munich, Germany), holding the chair of the Institute of Astronautics (space technology) at the University's faculty of mechanical engineering. In 2008, he was distinguished as Professor of the Year 2008 in the category "engineering sciences and computer science".[2]
He serves on the advisory board of Deutsches Museum,[3] on the advisory council of Giordano Bruno Foundation, and he is president of the Hermann Oberth Space Travel Museum in Feucht. He is the author of several books, including the illustrated book "In 90 Minuten um die Erde" ("Around the World in 90 Minutes"), and he has published more than 80 articles in various international journals.[2]
