The peaceful use of space flight systems for research and technological devel- opments in the context of promoting European and international cooperation represents the essential motivation for the programmes of the European Space Agency (ESA). One of ESA's programmes is dedicated to microgravity research, which is now an established discipline in Europe, with a dedicated group of scientists participating. The Challenger disaster has resulted in a serious dis- continuity of flight opportunities in the next few years but the forthcoming International Space Station, new launchers and reentry...