ARED Space Exercise Simulator

The Advanced Resistive Exercise Device (ARED) is how ISS crews fight the roughly 1–2% of muscle and bone mass astronauts would otherwise lose every month in microgravity. Free weights don't work with nothing pulling them down, so ARED loads the body with two vacuum cylinders instead: piston, harness, gas physics. This simulator renders the real mechanism — a piston moving through an evacuated cylinder whose resisting pressure follows Boyle's Law as the trapped volume changes — animates a harnessed astronaut driving it through reps, and feeds the resulting force into a dose-response model built from measured ISS outcomes, so you can see exactly how evacuation level, cylinder count, session length and weekly frequency trade off against projected monthly muscle and bone loss.