EIC Laboratories Inc. is proposing a lightweight multifunctional polymer/nanoparticle composite for radiation shielding during long-duration lunar missions. Isolated nanoparticles homogeneously dispersed throughout the polymer reinforce polymer matrices relative to conventional powder dispersion. This will enable the exploitation of the high hydrogen density of the polyolefin while improving the mechanical and structural properties of polymer composites used in radiation shielding. The goal of this program is to demonstrate that hydrogen dense polyolefins loaded with neutron shielding nanoparticles demonstrate improved shielding and mechanical properties relative to commercially available alternatives. In Phase I, polyolefin/nanoparticle-shielding composites will be fabricated and characterized for thermal, mechanical, and particle dispersion properties relative to commercial products.