"This symposium was organized to bring together the multidisciplinary expertise required to assess risk of exposure to space radiation.... Topics addressed ranged from what is known or predicted about radiation environments for human exploration, and what shielding would be required based on ALARA radiation protection guidelines. The development of new physics cross section models, and improved ion beam transport codes was reported, as well as biological demonstrations of the consequences of specific shielding materials and applications to manned missions to Mars and beyond. Advancements in the biological measurements of radiation-induced protein expression profiles, membrane damage, bystander effect, and adaptive response were presented, and countermeasures evaluated. Finally several presentations addressed specific approaches to integrate the physical and biological parameters in order to assess key elements of the risk and the associated uncertainties."--Page 1277.