Anthropometric Human-Spacesuit Modeling Developments for Lunar Dynamic Loading Injury Scenarios

Lunar surface exploration will inherently expose humans to dynamic loading conditions in spacecraft and vehicles, where risk of injury can occur. In Lunar Terrain Vehicle (LTV) driving scenarios, the crewmember operates the vehicle while wearing a spacesuit, which increases the risk of blunt and repetitive contact injuries as the body collides with the internal components of the spacesuit. To assess injury risk, NASA uses Finite element (FE) human body models (HBMs) to derive injury metrics from dynamic loading forces/accelerations. It is important that astronaut anthropometry can be accurately represented in these models as injury mechanisms will change for different crewmember body shapes and sizes. At NASA, the Global Human Body Models Consortium (GHBMC) 5th percentile female, 50th percentile male, and 95th percentile male HBMs are used to assess dynamic loading. An anthropometric evaluation of these models indicates that they do not fully represent spacesuit anthropometric requirements. There are tools to adjust the body shape of HBMs such as the Position and Personalize Advanced Human Body Models for Injury Prediction (PIPER) software, but the default morphing pipeline is limited at representing subtle body shape morphology. Therefore, custom control point selection from 3D body scans and morphing algorithms are being systematically investigated to improve scaling of the GHBMC models. Initial results from a proof-of-concept example were encouraging as the morphed torso segments closely approximated the original scan data. Anthropometrically accurate HBMs will enable effective occupant protection injury assessments and inform key hardware designs in the context of crewmember safety.