This proposal aligns with NASA stennis space center s technical requirements related to energy harvesting and nuclear thermal propulsion system testing, and anticipates that results will help reduce…

This proposal aligns with NASA stennis space center s technical requirements related to energy harvesting and nuclear thermal propulsion system testing, and anticipates that results will help reduce mission risk to near-earth objects, mars, and other deep space destinations, as well as help advance technologies related to ground testing of these systems. Cosmic radiation is the critical obstacle preventing extended human space exploration. There is currently no practical application which can fully reproduce the shielding effect produced by the earth s strong magnetic field in combination with dense atmosphere. Since extended missions to the moon and mars are in the NASA s space technology roadmap, a tremendous amount of research is therefore focused upon inventively finding ways that will reduce radiation exposure both in transit, and at the final destination in space. An innovative solution is to take advantage of the native shielding properties of the planetary material itself, and utilize and/or create subsurface structures with IT. However, due to the extreme cost of up-mass (payload from earth to space), little real consideration has been given to the implementation of true construction materials. Therefore, to address this need, we propose to construct materials that provide both (1) durable structural support as well as (2) increased radiation shielding properties, and can be created in situ, almost entirely from materials that can be readily obtained from the surface of the moon or potentially other planets. Geopolymers are inorganic cementitious binders produced by polymeric reaction between an alumino-silica rich material and an alkali metal hydroxide/silicate liquid, forming a binding GEL, which can be used to encapsulate fine and coarse aggregates to produce concrete. While earth-based applications utilize commonly available materials, such as metakaolin, fly ASH, or even rice husk, researchers at the trenchless technology center (TTC) under the direction of DR. Erez allouche have reproduced lunar regolith to make geopolymer concrete specimens (`lunamer ) by activating the regolith with alkali liquid (figure 1). The samples exhibited a 3-day compressive strength of 1600 PSI; with the moon s gravity level being 1/6TH that of earth, this translated into an equivalent strength of 9,600 PSI in earth terms, double the compressive strength of most concrete structures built on earth. Geopolymer binder technology presents superior mechanical and thermal performance, and has been shown to be compatible with an abundantly available lunar resource (lunar regolith) (montes and allouche, 2012). Therefore, to understand space-based applications, next steps should include characterizing radiation shielding effectiveness