Space Medicine

Crews run on a harness-tethered treadmill and pedal a cycle ergometer for hours each week to keep the heart and muscles conditioned against the deconditioning of weightlessness.

Spinning a spacecraft or a short-radius centrifuge to create an outward force that mimics gravity. A long-studied but not yet operational countermeasure that could address many effects of weightlessness at once.

The heart and blood vessels adapt to weightlessness, and the heart can weaken without the constant work of pumping against gravity. Crews often experience orthostatic intolerance — dizziness on standing — when they return to gravity.

Spaceflight alters the immune system — some functions are dampened while latent viruses can reactivate — a concern for crew health on long missions far from medical care.

Carefully planned diet and supplementation — adequate energy, protein, vitamin D, and controlled sodium — works together with exercise to protect bone and muscle and to support overall crew health.

A device that applies suction to the lower body, pulling fluids back toward the legs as gravity would. It is studied as a countermeasure to the headward fluid shift and the eye changes of SANS.

The biomedical sensors, health checks, and ground-linked telemedicine that watch over crew health in flight. On missions to Mars, where help is minutes-to-hours away by radio, crews will need to be far more medically autonomous.

Medications used to protect crew health — bone-preserving drugs studied against spaceflight osteopenia, and medicines that manage space motion sickness, sleep, and other conditions in flight.

Weightlifting in orbit. Devices such as the ISS's Advanced Resistive Exercise Device let crews load their bones and muscles against a resistance in place of gravity — the single most important countermeasure against bone and muscle loss.

In the first days of flight, the conflict between the eyes and the balance organs of the inner ear causes disorientation and nausea as the brain adapts to weightlessness; a mirror-image readaptation occurs on return to gravity.