Spacesuit outer-shell OrthoFabric in low-temperature space environments: tensile response and damage evolution

OrthoFabric, the dual-layer woven material currently used as the outer-shell of NASA spacesuits, must be able to withstand extremely low temperatures and high mechanical demands of future space missions. In this study, we investigate its tensile response and fracture mechanisms across temperatures ranging from room temperature (300K) down to cryogenic conditions (77–24K), representative of the Moon’s permanently shadowed regions. Results show that while tensile strength remains largely comparable across temperatures down to 48K, elongation at rupture decreases sharply with decreasing temperature, with maximum elongation reduced by more than 60% under cryogenic conditions. A marked drop in tensile strength is also observed at 24K. Room-temperature tests reveal progressive damage involving sequential yarn failures and disruption zones, whereas cryogenic tests exhibit abrupt failure with limited damage propagation. Extension-rate sensitivity is evident, with tensile strength reduced at slower extension rates, particularly at room temperature. Microscopic post-mortem analyses highlight the role of PTFE stiffening and its glass transition in governing the overall response. These findings establish baseline cryogenic performance data for OrthoFabric, providing fundamental insights into its limitations and guiding the design of next-generation outer-layer fabrics for future extravehicular activity missions.