Potential Impact/Benefits: Radiation protection is an enabling technology for future exploration missions. The Agency cannot support human missions greater than approximately 90 to 100 days beyond LEO without developing shielding and/or biological countermeasures to remain below Permissible Exposure Limits. The Success Criteria are adequate shielding measures to enable safety of crew and hardware during long duration human missions up to 1 year in space. It is the intent of the proposed research to bring the Agency closer to extending space missions beyond the 100 days, with 1 year as a long term goal. Hydrogen, boron, and nitrogen based materials can provide mechanically strong, thermally stable, structural materials with effective radiation shielding against GCR, neutrons, and SEP. Preliminary neutron exposure tests at LaRC on BN containing polymers and BNNT containing polymers showed great promise for radiation shielding. Lightweight durable multifunctional materials in all forms are needed for radiation protection for both humans and microelectronic components. Electronic components become more vulnerable to particulate radiation (including neutrons, protons, and heavy ions) as their size shrinks and the operating voltage is reduced. Microelectronics in future aerospace vehicles and medical applications, such as pacemakers, require effective lightweight radiation shielding materials such as transparent or nontransparent hydrogenated BNNT composite coatings or layers. To our knowledge, no experimental or computational studies have been done on the radiation shielding properties of BN and BNNT containing polymers, except for our preliminary experimental study. The proposed research will provide a systematic assessment of the fundamental radiation shielding properties of the proposed materials (TRL = 1-2).
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