Merbold was born on June 20, 1941 in Greiz, Germany -- by chance just 40 kilometers from where Sigmund Jähn, the first German in space, was born. After he finished school in 1960, he left East Germany and settled in West Germany. He studied physics at the University of Stuttgart, earning a diploma in 1968 and a doctorate in 1976. He then joined the Max-Planck-Institute for Metals Research in Stuttgart, where he worked on solid state physics and low temperature physics.
In 1978 the European Space Agency (ESA) selected him, together with Wubbo Ockels and Claude Nicollier, to train as payload specialists on the first flight of the Spacelab module. In 1982 he was selected as the prime payload specialist, and in 1983 he flew on board the Columbia on the STS-9 mission.
1986 he transferred to the European Space Technology Center (ESTEC) to work on the European Columbus module for the International Space Station. In 1986 he also became Head of the Astronaut Office of the German spaceflight organization DLR.
In 1988 NASA nominated Ulf Merbold as payload specialist on the IML-1 mission, which launched on STS-42 in January 1992. The following year he was Science Coordinator for the second German Spacelab mission, D-2 (STS-55).
In 1993 he also started training to fly the first of two joint European-Russian missions to the space station Mir, called Euromir 95. In 1994 he was the first ESA astronaut to fly into space with Russia, on board Soyuz TM-20. During his three spaceflights he spent a total of 49 days, 21 hours and 38 minutes in space.
Ulf Merbold is still working for ESA in the Microgravity Promotion Division of the ESA Directorate of Manned Spaceflight and Microgravity at ESTEC, but he is no longer a member of the European astronaut team.