Exobiological experiments in earth orbit

The primary goal of exobiological research is to reach a better understanding of the processes leading to the origin, evolution and distribution of life on Earth or elsewhere in the universe. In this endeavour, scientists from a wide variety of disciplines are involved, such as astronomy, planetary research, organic chemistry, palaeontology and the various sub disciplines of biology. Space technology plays an important part by offering the opportunity for exploring our solar system, for collecting extraterrestrial samples, and for utilising the peculiar environment of space as a tool. Exobiological activities in Earth orbit include studies on the survival of resistant life forms in space. During previous space missions, such as Gemini Spacelab, LDEF, Foton, MIR and EURECA, exposure of various microorganisms to selected and combined space conditions has demonstrated the enormous lethal potency of extraterrestrial solar UV radiation. However, when efficient shielding is provided against the influx of solar UV radiation, bacterial spores cope with space for more than 5 years without any loss of viability. Future research, e.g. on the space station by use of the SEBA facility, will provide clues towards our understanding of the relevance of extraterrestrial organic molecules to the emergence of life on Earth or any other planet, the role of solar UV radiation in evolutionary processes, related to life, the chances and limits for life to be transported from one body of our solar system to another or beyond, and of exobiological phenomena in aerosols and clouds. (C) 1998 COSPAR. Published by Elsevier Science Ltd.