Life-support systems are used by astronauts to recycle oxygen and guarantee a steady supply.
Vigorous exercise combats the loss of bone and muscle caused by zero-gravity circumstances.
Water from perspiration and urine is recycled by astronauts using sophisticated filtration devices.
Nutrient-dense, specially packaged meals help astronauts stay healthy during extended flights.
Astronauts are protected from dangerous exposure to solar and cosmic radiation by spacecraft walls.
Psychological activities assist astronauts in coping with stress and loneliness in cramped environments.
Astronauts are shielded from the harsh space temperatures by spacesuits and spacecraft controls.