Life Sciences in the Space Program 



Radiation Biology 



Findings 



• Much needs to be learned about the radiobiological effects of high LET 

 radiation, an issue central to establishing a long-term human presence in space. 



• The importance of this research to NASA stems from a number of factors: the 

 pervasiveness of GCR and secondary radiation in space environments relevant 

 to NASA missions, the high biological effectiveness of high LET radiation, the 

 differences in effects between low and high LET radiations, and the early stage 

 of this field's development. 



• Work is needed to establish the relative biological effectiveness for HZE 

 particles, to investigate the low dose-rate effect of high LET radiation relevant to 

 such topics as carcinogenesis, cataractogenesis, embryonic development, and 

 the functioning of the nervous system, and to provide a basic theoretical basis 

 for radiobiology and track structure. 



• Additional attention needs to be directed to the development and evaluation of 

 radioprotectors, the interaction between ionizing and ultraviolet radiation, and 

 possible interactions between environmental stresses to the organism and 

 radiation. 



Recommendation 



• NASA should vigorously pursue basic research in the radiation biology of 

 high LET radiation. 



Shielding and Transport 



Findings 



• More complete knowledge of radiation-shielding interactions is necessary to 

 determine radiation risk factors for the mission crew and to design adequate 

 protection. 



• This effort requires measurement of the free-space radiation environment, 

 measurement of the radiation environment within the spacecraft, and 

 accelerator-based experiments designed to studv the interaction of radiation and 

 matter. 



• Parallel research efforts in the modeling of these interactions will result in 

 transport codes (computer programs that simulate the passage of each type of 

 radiation through defined series of materials) that can be used for the design 

 and evaluation of a range of situations. 



Recommendation 



• NASA should direct the following efforts to work in shielding and 

 transport research: conduct measurements of the free-space radiation 

 environments; study the interaction of radiation with shielding materials 

 through the development of the transport computer codes and accelerator 

 experiments. A balanced approach in studying the free-space radiation 





