Consideration of Spacesuit Stepping Mobility for Lunar EVA Crew Interface Design

As NASA aims to take humans back to the moon's surface through the Artemis Campaign, careful considerations regarding suited human factors in partial gravity are required during crew interface design to reduce overall NASA program risks. The unique environment of the lunar surface presents significant challenges for human mobility, particularly while wearing a spacesuit. Given the altered spacesuit kinematics, defining proper step or platform heights that are safe and accessible for suited crewmembers across the anthropometric range is an important aspect of human factors in spacecraft design. In this work, an analysis was performed using a 3D spacesuit model scaled appropriately to specific anthropometric properties, then combined kinematics data gathered during previous spacesuit data collection events using a motion capture system. The kinematics data previously collected included tasks such as suited test subjects performing forward steps up onto a surface and sidesteps over an obstruction on the floor. The collected data were then projected onto a virtual wearer, whose anthropometry corresponded to a 1st percentile female and a 99th percentile male in stature and vertical trunk diameter (VTD) to assess different what-if scenarios for extreme anthropometric ranges. The influences from other crew interface configurations, such as handle placement, were also investigated. This paper demonstrates how suited test data integrated with human-suit modeling can effectively be used to develop recommendations for EVA systems requirements. These recommendations are expected to reduce biomechanical stresses and risk of injury for the crewmembers while improving EVA mobility and performance.