(444d) Development of a Predictive Model for in-Situ Resource Utilization of Space Exploration Waste

As we prepare for exploration-class human space missions, readily available, in-situ resources must be identified and prioritized. Through this lens, resource recovery from astronaut waste items becomes increasingly advantageous. With an approximate waste production rate of 1.8 kg per crewmember per day, considerable resources can be extracted from these waste materials as mission durations increase and sustainable on-planet surface architectures are developed. To estimate waste item production and resultant resource availability, an updated waste model for exploration was developed. This model incorporates up-to-date trash production estimates from the International Space Station, along with expected changes for deep-space exploration missions. To quantify the available resources outlined in the updated waste model, an elemental analysis of each major waste category was performed via CHONS elemental analysis and quantitation. Moisture content for current NASA waste models, along with user-inputted custom waste models, were also analyzed. Furthermore, NASA waste management technologies for exploration were integrated into the model to predict performance differences as the amount and composition of input waste feedstock varies. These technologies include Trash-to-Gas (thermal degradation of astronaut waste items into a syngas), Trash Compaction and Processing System (compaction of astronaut trash and recovery of water), and In-Space Manufacturing (3D printing of processed and recovered waste materials). Key performance parameters for each technology were assessed as a function of various space mission parameters – mission duration/location, crew size, trash feedstock, and trash production rate. An overview of the key findings from this study, including resource estimates from waste items for near-term human missions, is reported.