Human physiology adaptation to altered gravity environments

International audience; Multiple transitions between gravity levels will occur during planetary exploration missions. In reaction to these gravitational transitions, physiological adaptation will be initiated. However, the physiological effects of longduration exposures to hypogravity and hypergravity are poorly understood. In this review we present an overview of how humans perceive gravity, review sex-based differences in adaptation to changes in gravity, and introduces rather limited evidence currently available related to the effects of partial gravity. The paper then argues that there is a need for more research to better understand the extent and dynamics of physiological adaptation mechanisms during gravity level transitions in spaceflight and proposes a need for artificial gravity (AG) as a multi-system countermeasure and explore the efficacy of AG as countermeasure between short and very long-arm centrifuges. Discussed here are the effects of acute short-arm AG application. The topical review also discusses the usage of chronic AG application via the innovative large-radius Hypergravity Human Habitat, H 3 , concept.