A Consolidated Tool for Planning and Analyzing Simulated Exploration Traverses and Associated Metabolic Workload

Planning exploration extravehicular activity (xEVA) traverses on the lunar surface requires the identification of an optimized path that meets scientific and mission objectives with consideration of obstacles or restricted areas. It is also essential to estimate the physical and metabolic effort the crewmembers will expend as they navigate more complex and challenging Lunar south polar terrain, characterized by intricate features such as craters and mountains while conducting geologic and in situ resource utilization tasks. An accurate estimation of metabolic expenditure is necessary to inform mission planning as it relates to spacesuit life support consumables. This paper describes a novel xEVA traverse model with a pathfinding function based on a hybrid A* algorithm that includes elevation, gradient, and rollover heuristics. The traverse model incorporates estimates of crewmember metabolic rate during traverse, enabling the planning of safe, efficient, and successful xEVA across terrestrial, Lunar, and Martian terrains. Model inputs and outputs are summarized, showing the terrestrial traverse model equations' progression to improve accuracy in estimating metabolic cost compared to measured metabolic cost, with a linear regression coefficient of 0.95 (p < 0.01) and a mean reduction of 354 BTU/h compared to the metabolic rate estimation method used in the conventional EVA traverse planning tools. This consolidated tool for planning and analyzing simulated xEVA traverses and associated metabolic workload enables mission planning for energy-efficient path determination and can be further modified in the future to add additional suit and planning constraints for various mission concepts of operations.