Browsing by Author "Yates, Keegan"
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Item Comparison of Anthropomorphic Test Device and Human Volunteer Responses in Landing Impact Tests of U.S. Space Vehicles(2024 International Conference on Environmnetal Systems, 2024-07-21) Reiber, Teresa; Greenhalgh, Preston; Yates, Keegan; Somers, Jeffrey; Null, Cynthia; Thompson, Rachel; Drake, Aaron; Newby, Nathaniel; Gohmert, Dustin; Suhey, Jeffrey; Perry, Chris; Buhrman, John; Baldwin, MarkUnited States (U.S.) crewed vehicles are being designed to support the National Aeronautics and Space Administration�s (NASA�s) human spaceflight programs. Vehicles must be designed to meet NASA�s occupant protection requirements including landing injury assessment with anthropomorphic test devices (ATDs) and analytical models. However, these tools are limited in capturing all injuries that might occur during spacecraft landings. A NASA study of injuries during Soyuz vehicle landings has shown that analytical models are underpredicting occupant injury. Because of the inherent limitations with our analytical tools, human volunteer impact testing was employed to validate the safety of U.S. crewed vehicles. A total of 84 human volunteer tests in 11 different test orientations and g-levels were completed as part of this effort in collaboration with the Air Force Research Laboratory (AFRL) at Wright- Patterson Air Force Base and the vehicle development companies. Human subjects were tested at various realistic landing loads and in the highest fidelity seat and suit components that were available at the time of testing for two U.S. vehicles. Matched-pair ATD tests in the same test conditions were also conducted with small female and midsized male Hybrid III ATDs. ATDs were fully instrumented. Head accelerations and subjective responses were recorded in human subjects. In some cases, chest accelerations were captured. Responses of the ATDs and humans in matched-pair tests were compared. No ATD tests showed evidence for risk of injury based on NASA occupant protection requirements. Human subjects reported 17 cases of discomfort or pain, 1 human subject was diagnosed with a minor injury that was not evident in the ATD tests. These results provide evidence that ATDs do not capture all potential injury risks, namely lower severity injuries, discomfort, and pain. Overall, human testing is beneficial to understanding the true risk of injury to crewmembers during Earth landings.Item LTV-xEVA Applied Injury Biomechanics(2024 International Conference on Environmnetal Systems, 2024-07-21) Yates, Keegan; Drake, Aaron; Davis, KristineBeginning in Artemis V, Lunar Terrain Vehicles (LTV) will be utilized to enable astronauts to explore the lunar south pole and conduct science farther from the landing site than during the Apollo program. However, LTV operation has the potential to cause injury to the suited crew member during their Extravehicular Activity (EVA). Injury risk caused by LTV acceleration and jerk combined with blunt loading from rigid suit components needs to be better understood. An effort began to create requirements, model, and address the injury risk caused by the LTV combined with Exploration EVA (xEVA) suits. Mitigation of crew injury is a shared responsibility between LTV and the suit since neither can accomplish this independently. The modeling completed in Fiscal Year 2023 (FY23) helped to verify the fidelity of the requirements and parse out vendor responsibility (LTV, xEVAS, or NASA) for Artemis V+. The scope of the modeling in FY23 used the LTV System Requirements Document (SRD) as worst-case inputs and modeled female 5th, male 50th, and male 95th percentile subjects in hard-mounted seated and semi-standing postures. Soft-mounted (i.e. lap belt) and testing to validate the analysis was determined out of scope for FY23 work.