Solid core Nuclear Thermal Propulsion (NTP) has been identified as the advanced propulsion concept which could provide the fastest trip times with fewer Space Launch System (SLS) launches for human missions to Mars. However, current environmental regulations require NTP engine exhaust filtering of radioactive halogens, noble gases and particulates to stay within safe limits. Particularly high efficiency (greater than 99.5%) removal of radioactive halogens, noble gases and vapor phase contaminants is of specific interest to NASA. In this SBIR project, TDA Research, Inc. proposes to develop a novel high capacity sorbent to remove radioactive halogens and noble gases from NTP engine exhaust with an efficiency greater than 99.5%. This sorbent will be part of an effluent scrubber system, which initially cools the hot hydrogen exhaust with a water spray, and then further cools it and removes the water in a series of heat exchangers. In Phase I, we will prepare the sorbent and demonstrate its ability to selectively remove radioactive halogens and noble gases under simulated NTP engine exhaust conditions. Based on the performance results, we will carry out a preliminary design of the scrubbing system for NTP engine exhaust and estimate its size and cost.