Section headings and selected papers: Heavy-Ion Effects in Genetically Relevant Cellular Structures . Direct radiation action of heavy ions on DNA as studied by ESR-spectroscopy, A. Schaefer et al . Heavy ion induced double strand breaks in bacteria and bacteriophages, U. Micke et al . Heavy ion-induced chromosomal damage and repair, E. H. Goodwin & E. A. Bla;ely. Mutation induction in mammalian cells by very heavy ions, T. Kranert et al . Genetic changes in mammalian cells transformed by helium ions, M. Durante et al . Combined Effects: Radiation, Microgravity, Trauma and Other Factors . Human reproductive issues in space, P. A. Santy & R. T. Jen;ings. Combined injury syndrome in space-related radiation environments, R. F. Dons & U. Fohlme;ster. Comparative study of spermatogonial survival after X-Ray exposure, High-LET ( HZE ) irradiation or spaceflight, W. J. Sapp et al . Physical and Chemical Protection Against Ionizing Radiation . Role of endogenous thiols in protection, O. Vos. Some recent data on chemical protection against ionizing radiation, M. Fatome et al . Behavioral toxicity of selected radioprotectors, M. R. Landauer et al . Radiation Risk Assessment for Manned Spaceflight . Modeling the time-intensity profile of solar flare generated particle fluxes in the inner heliosphere, D. F. Smart & M. A. She;. Gamma-ray measurements from the space shuttle during a solar flare, P. S. Haskins et al . Radiation Protection Aspects Related to Human Missions to Mars . Radiation situation determining the possibility of a manned flight to Mars and back, N. F. Pissarenko. Effects of increased shielding on gamma-radiation levels within spacecraft, P. S. Haskins et al. Author Index.