German Clinical Trials Register

Acronym/abbreviation of the study

AGBRESA-Study

URL of the study

No Entry

Brief summary in lay language

Human spaceflight is currently entering the next phase of space exploration, namely towards the Moon and Mars. Linked to such ambitious goals are - by nature – physical, psychological and technological challenges which become increasingly difficult to understand and overcome with longer-duration missions: future exploration class missions may last up to several years, exposing astronauts to extreme environmental conditions and physical stressors that could cause major issues to both health and performance. Currently, some of these issues are considered as showstoppers for long-duration exploration missions with human crews. To safeguard astronauts’ health, well-being and working efficiency, a comprehensive strategy to mitigate various risks is therefore required, including development of so-called countermeasures to reduce adverse responses to stressors stemming from exposure to the space environment. Over the past 50 years of human spaceflight experience, a palette of countermeasures has been developed and tested, but they have had only limited success. This may be explained by the fact that currently applied countermeasures mitigate harmful responses of specific systems of the human body. Future countermeasures, therefore, have to be approached in an interdisciplinary manner. Because all physiological systems are challenged through the application of artificial gravity (AG) by centrifugation, it has been considered that AG has the unique feature of being a multi-system countermeasure for mitigating the effects of weightlessness. The primary objective of the AGBRESA bed rest study is to compare the protective effects of one single daily bout (30 min) versus multiple daily bouts of AG (6 x 5 min) on physiological functions that are affected by simulated weightlessness. A secondary objective is to document the user’s point of view, such as subjective rating of comfort/discomfort, perceived exhaustion, perceived benefits, and any other psychological issues associated with the AG protocols. The research in this bed rest study is proposed and will be performed by international established research teams and characterizes changes in physiological and psychological systems; systems of interest include, but are not limited to musculoskeletal, sensorimotor, cardiovascular, cerebrovascular, ocular, functional performance, cognition and behavioral health.

Brief summary in scientific language

Weightlessness causes multiple physiological changes in the human organism. The absence of gravity results in a loss of mechanical loading of the muscles and bones, a redistribution of fluids in the body and changes in the acid-base balance (mostly for dietary reasons), which for their part lead to gradual reduction of bone, cartilage and muscle mass, mainly in the lower extremities; deconditioning of the cardiovascular system; alterations of metabolism and cognitive performance. Aware of these changes, spaceflight missions were soon complemented with preventive measures, or ‘countermeasures’ in the human spaceflight context, to alleviate or completely prevent deconditioning of the human body. However, some 50 years later, the currently employed countermeasures are to some extent still insufficient. Maintenance of astronaut safety and wellbeing is imperative for successful future long-duration spaceflight missions on board the international space station ISS, to the Moon and eventually to Mars. Artificial gravity (AG) generated by centrifugation has the potential to mitigate physiological deconditioning caused by prolonged exposure to weightlessness. Because all physiological systems are challenged through the application of AG, it has been considered that AG has the unique feature of being a multi-system countermeasure for mitigating the effects of weightlessness. While it is obvious that AG cannot address all of the problems associated with long-duration spaceflight, there is scientific consensus that AG offers the potential to address the debilitating problems of bone loss, cardiovascular deconditioning, muscle weakening, sensorimotor and neurovestibular disturbances and regulatory disorders. In contrast to traditional countermeasures, AG can be considered as an integrated countermeasure because it addresses all of these systems at once. Therefore the use of AG might be the best solution for human health protection during human long-duration deep space missions.