Future space explorers will encounter physiological challenges due to prolonged exposure to a microgravity environment. The exposure effects contain musculoskeletal system and cardi-ovascular deconditioning, including orthostatic intolerance (OI). This becomes a problem when returning to a gravity environment, which affects cerebral blood flow and can lead to syncope, affecting crew performance and the success of space missions. Artificial gravity (AG) is a potential countermeasure against spaceflight deconditioning and OI, generated by centripetal acceleration through a short-arm human centrifuge (SAHC). While studies have shown positive effects and adaptations of human physiology to AG, limited attention has been given to seasonal variations affecting artificial gravity tolerance (AGT). This study aims to analyse differences in AGT across different seasons and their potential impacts on cardio-vascular parameters. We hypothesized that AGT would be greater during colder seasons due to known influences of seasonal changes on the cardiovascular system. To test this hypothe-sis, we compared two AGT studies, each following two equivalent protocols, but at different times of the year. The AGT results from both tests were compared, and a correlation was drawn with the seasons. AG from 0.6 G to 1.7 G was used, and AG was increased by 0.1 G at each step. Each step from 0.6 G to 1.7 G lasted for 3 minutes until the participant experi-enced pre-syncopal symptoms. AGT time was determined based on the occurrence of pre-syncope symptoms. Artificial gravity tolerance was higher during winter sessions. Significant variations were observed in the rate of change of blood pressure (BP) across seasons during the AGT studies (p < 0.05). The rate of change of BP during AG runs was higher in summer sessions and more consistent in winter sessions. Seasonal variations in AGT were found, with higher tolerance and more consistent BP responses observed during winter. These find-ings suggest that environmental factors, such as temperature, may influence human physio-logical responses to AG, with implications for future space mission planning. Our results demonstrate the importance of understanding AGT variations for optimizing crew health and performance in space missions. Additionally, insights gained may contribute to the under-standing of physiology and cardiovascular changes in aging, with implications for clinical problems in terrestrial medicine for example geriatrics.
Individualized Artificial Gravity Effects Across Seasons
Millek, J. M. (Author). 2024
Student thesis: Diploma thesis