The limitations of current NASA standards addressing standing landings include lack of data and lack of robust analogs within that data. The human drop tests and their various conditions conducted in this study will add a substantial amount of human performance and kinematic data and will provide the most accurate analog possible to replicate lunar landings while standing. While these human volunteer tests will be conducted at non-injurious levels, they will determine loading conditions that are tolerable as related to human performance. Because of the appropriateness of very low injury risk for lunar missions, a better understanding of the human tolerance to these drop conditions will act as a barrier to protect against injury.

Each subject will conduct simulated lunar landings with various conditions, including landing pulse, landing angle, and restraint type. Various methods of assessment will be used to qualitatively and quantitatively measure performance of each subject from each simulated landing. Subjects will be outfitted with IMUs (inertial measurement units), and accelerometers and load cells will measure loads and moments of each subject's reaction to simulated lunar landings. This data, combined with survival analysis methodology, will associate variables that accurately predict performance loss.

The data collected from the instrumented subjects will also be provided to other funded research studies investigating computational standing landing model verification and validation. This study will provide a robust data set with many test subjects and many test conditions that is needed to train and verify these models.

The subject performance analysis, coupled with instrumentation data, will also be used to estimate parameters for a standing human spring-mass-damper model. These types of models are already used in spaceflight to estimate the human response and risk of injury while seated. This work will create a new model capable of estimating the human response while standing and estimate loss of performance. This type of model is simple but provides a straightforward method of prediction that is applicable to a large range of potential landing conditions that are not possible to fully replicate with other complex methods.

Lastly, the study will assess the effects of restraints and suits on human performance during standing landings. Comparisons between restrained and unrestrained conditions will be used to measure the effectiveness of basic restraint systems to improve human performance. While the proposed work is not intended to include an exhaustive study of the effects of restraints and suits on crewmember performance during standing landings, the results from this study will inform how future studies could more extensively study the effect of restraints and suits on human performance.

Because the findings of this study involve understanding crew performance and injury risk, the findings and impacts from this study are applicable beyond the NASA Human Research Program (HRP). Additional customers include the Human Landing System (HLS) program, HLS providers, the Health and Medical Technical Authority (HMTA), and the Office of the Chief Health and Medical Officer (OCHMO).