The crew of the STS-55 Space Shuttle Columbia, for the dedicated German Spacelab D2 mission, were: (back, from left) Bernard Harris, Hans Schlegel, Jerry Ross, Ulrich Walter, (front, from left) Tom Henricks, Steven Nagel and Charles Precourt. STS-55 was launched on 26 April 1993. Hans and Ulrich were astronauts working for the German space agency DLR. Hans joined the ESA astronaut corps in 1998.