I studied medicine in Marburg, Germany and started my specialisation in nuclear medicine in 1985. In 1989 I joined the German Aerospace Research Facility (DLR) as a flight surgeon for the German D0-2 Spacelab mission. I supported a total of 9 Space-Shuttle and 3 MIR missions in this function.

In 1995 I moved on to the European Astronaut Centre of ESA in Cologne and became the Head of Space-Medicine in 1998. A dedicated medical mission control facility was established and a team of biomedical engineers, IT specialist, nurse, physicians, sport scientists, physiotherapists and psychologists was setup in order to support the upcoming long-duration spaceflights to ISS.

Together with King's College in London a new Master program "Space Physiology and Health" was developed with the goal to establish dedicated space-medicine tracks enabling the education and recruitment of future space-medicine experts.

In January 2016 I joined the ISU on a secondment from ESA as a visiting professor, covering the domain of "Human Performance In Space" (HPS). Since fall 2017 I am full professor and ISU faculty member.