This volume is based on the proceedings of an Advanced Study Institute (ASI) sponsored by the North Atlantic Treaty Organization (NATO) held October 1987 in Corfu, Greece. The Institute received financial support from the National Aeronautics and Space Administration, U.S.A. Armed Forces Radiobiology Research Institute, U.S.A. Department of Energy, U.S.A. Deutsche Forschungs-und Versuchanstalt fur Luft und Raumfahrt e.v., Kaln, Germany The advent of the shuttle era is providing fresh impetus for large space ventures such as communication centers, solar power stations, astronomical...