Musculoskeletal

Space exploration presents an extraordinary physiological challenge to the human body. In the absence of Earth’s gravity, every organ system of the human body must adapt to an environment it was never designed for. From disorientation and motion sickness, cardiovascular conditioning, blurred vision, to the loss of bone and muscle, the consequences of microgravity are wide-ranging and complex.
Over the past 5 decades, medical research—both in orbit and through ground-based analogs—has significantly deepened our understanding of how microgravity alters human physiology and has guided the development of countermeasures to protect astronauts’ health. This article summarizes the major medical effects of microgravity, the underlying mechanisms that drive them, and the countermeasures currently in place or under investigation to mitigate these challenges.