Large scale cooling in space is "solved" but it is not easy. The ISS cools itself with radiators using ammonia. https://www.nasa.gov/content/cooling-system-ke

Large scale cooling in space is "solved" but it is not easy. The ISS cools itself with radiators using ammonia. https://www.nasa.gov/content/cooling-system-keeps-space-station-safe-productive https://www.nasa.gov/content/cooling-system-keeps-space-stat... https://en.wikipedia.org/wiki/External_Active_Thermal_Control_System https://en.wikipedia.org/wiki/External_Active_Thermal_Contro... The mind boggles trying to imagine what a data-center sized cooling system designed to reject heat solely through radiation and optimized principally for weight looks like.