Human space exploration is a critical aspect of space sciences. Although robotic probes are invaluable for preliminary studies or high-risk environments, humans are able to solve problems, improvise, and make discoveries that are not programmed into a probe's software. Keeping astronauts safe and healthy while in space is a major concern. Non-astronauts take for granted many of the life support concerns that astronauts must consciously address to ensure their mission's success. Variables include gas requirements, temperature, gravity, radiation, and pressure. Waste products must be carefully monitored, and disposal or recycling must be planned. When astronauts leave Earth, many plans, procedures, and backup systems are in place for their comfort and survival.

Diagram showing the flow of water recovery and management in the International Space Station (ISS).

Temperature

During a space mission, astronauts and their spacecraft are exposed to temperature extremes on both ends of the scale...