Every spacecraft needs a life support system to sustain human life. The term environmental control and life support system or ECLSS for short is used to call this life support system.

This system provide air, water and food. It also regulates the correct body temperature, pressure in the cabin and deals with human waste. It includes also shielding against harmful radiation and micro-meteorites. (Credit:en.wikipedia.org/wiki/Life_support_system & phys.org)