International Space Station temperature control is a good deal more important than keeping things inside comfortable. It is a critical system that keeps the station liveable and enables important scientific equipment to conduct the microgravity research that is the station’s primary reason for being` The station has two external cooling loops. The two loops circulate ammonia outside the station through giant radiators to keep the station cool. When major abnormalities develop, some equipment is moved to the other loop for cooling and other equipment powered down. Such a failure doesn’t place the crew in any immediate danger nor does it necessarily disrupt activities. It does remove redundancy, which could make a second failure a far more serious concern. Loop A and Loop B are supported by Control Pump Modules that regulate the flow and temperature of the ammonia as it circulates. Temperature is controlled by passive measures – insulation, thermal coatings, heaters and heat pipes — and by an active thermal control system.