During interplanetary travels, space radiations are always crucial to spacecraft design due to their extreme hazards to human beings and electronics. Conventional materials, such as aluminum and other heavy metals, have been widely used on spacecraft. The cost of launching overweighed items to space is still high even reusable rockets are available now. Reducing weight of shielding structures on spacecraft will largely benefit future space missions. Nanocomposites with extreme low density but high radiation shielding properties are proposed in this project.