Space Medicine: Fluid Shift & Bone/Muscle Loss

This simulator visualizes what microgravity actually does to the human body over the course of a spaceflight mission. A 3D astronaut figure responds to two independent, real physiological processes: cephalad fluid shift, where the loss of gravity's downward pull lets body fluid redistribute toward the head and chest — driving the puffy-face/bird-leg appearance and raised intracranial pressure implicated in SANS — and bone/muscle deconditioning, where skeleton and muscle no longer bearing body weight are progressively resorbed at roughly 1–2% bone density per month. Drag the mission-duration slider to see both effects accumulate over a real ISS-length stay, and toggle countermeasures — resistance exercise and lower body negative pressure — to see how far modern spaceflight medicine can push back against physics.