Countermeasures
How crew health is protected — exercise, nutrition, shielding, lighting, and psychological support.
- Aerobic ExerciseCountermeasure
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.
- Artificial GravityCountermeasure
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.
- Circadian LightingCountermeasure
Tunable LED lighting that shifts colour and intensity through the day to reinforce the body clock, helping crews sleep and stay alert despite sixteen orbital sunrises a day.
- In-Flight NutritionCountermeasure
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.
- Lower-Body Negative PressureCountermeasure
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.
- Medical Monitoring & TelemedicineCountermeasure
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.
- Pharmacological CountermeasuresCountermeasure
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.
- Psychological SupportCountermeasure
The measures that sustain crew mental health — private family conferences, care packages, meaningful scheduling and rest, and ground-based behavioural health teams — increasingly important the farther a crew travels from Earth.
- Radiation ShieldingCountermeasure
Protecting crews from space radiation with mass — hydrogen-rich materials, water, or regolith — and with mission design, such as storm shelters for solar particle events and limits on time beyond the magnetosphere.
- Resistive ExerciseCountermeasure
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.