Space radiation concerns for manned exploration

Spaceflight exposes astronaut crews to natural ionizing radiation. To date, exposures in manned spaceflight have been well below the carter limits rec ommended to NASA by the National Council of Radiation Protection and Measur ements (NCRP). This will not be the case for long-duration exploratory clas s missions. Additionally, International Space Station (ISS) crews will rece ive higher doses than earlier flight crews. Uncertainties in our understand ing of long-term bioeffects, as well as updated analyses of the Hiroshima, Nagasaki and Chernobyl tumorigenesis data, have prompted the NCRP to recomm end further reductions by 30-50% for career dose limit guidelines. Intellig ent space craft design and material selection can provide a shielding strat egy capable of maintaining crew exposures within recommended guidelines, Cu rrent studies on newer radioprotectant compounds may find combinations of a gents which further diminish the risk of radiation-induced bioeffects to th e crew. Published by Elsevier Science Ltd. All rights reserved.