At the beginning of space flight, the investigations were oriented essentially toward the health of the astronauts. But in the last three decades space biology has evolved from "try-and-see" experiments to sophisticated basic and applied research with well-based hypotheses as well as studies on the use of low gravity in biological applications. In 1977 the Space Biology Group of the Swiss Federal Institute of Technology, Zurich, began its activities in space research. A summary of the experiments performed to date, from basic research on the human immune system to the development of sophisticated instruments for biotechnology and medical application, is presented here.