Ulrich Walter was born on 9 February 1954 in Iserlohn. After completing his secondary school education and national service, he began studying physics at the University of Cologne (Universität zu Köln) in 1974, completing his degree in experimental physics in 1980. His scientific career gathered pace and he received his doctorate in solid-state physics five years later, after which he moved to the Argonne National Laboratory in Chicago. In 1986 he transferred to the University of California at Berkeley.
A year later, he was selected as a German astronaut candidate and commenced training at DLR in 1988. Walter was selected for a mission alongside his German colleague Hans Schlegel in 1992.
On 26 April 1993 the two Germans launched along with five other astronauts aboard STS-55; their own national assignment was known as the 'D2' mission. Space Shuttle Columbia carried the second German mission for the multi-purpose space laboratory, Spacelab, into orbit. The crew performed 90 experiments during the multi-disciplinary mission in fields such as material and life sciences, technology, automation and robotics, as well as Earth and space observations. DLR, NASA, the European Space Agency (ESA) and other French and Japanese agencies collaborated on the mission. The crew worked around the clock on a split-shift basis. Many of the experiments augmented the D1 mission undertaken seven years previously. Among the many experiments carried out on the crew was the first test of how people react to saline injections, which was intended to determine their usefulness as a possible countermeasure to fluid deficiency. Furthermore, the Shuttle Amateur Radio Experiment (SAREX) gave students and amateur radio operators the chance to communicate directly with the astronauts.
After concluding the mission, Walter returned to Germany where he headed the development of DLR's German satellite imaging database (Deutschen Satellitenbild-Datenarchivs) at Oberpfaffenhofen, Bavaria from 1994, for four years. The result was a centralised repository for satellite images available to the public at large. Following a detour to the private sector, Walter has been the Chair of Aerospace Technology at the Technical University of Munich (Technischen Universität München) since 2003.