Orbital data center refrigeration requires novel architecture because standard cooling systems depend on gravity for fluid management and convection

Standard terrestrial refrigeration systems face fundamental physics barriers in microgravity environments. Natural convection—where heat rises via density differences—does not occur in microgravity, eliminating passive heat transfer mechanisms. Compressor-based cooling systems rely on gravity to separate lubricating oil from refrigerant; in microgravity, oil can migrate and clog the system. This is distinct from the radiator scaling problem (which is about heat rejection to space) and represents a separate engineering challenge for the refrigeration cycle itself. Technical experts quoted in the FCC filing analysis noted that 'a lot in this proposal riding on assumptions and technology that doesn't appear to actually exist yet,' with refrigeration specifically called out as an unresolved problem. This suggests orbital data centers require either novel refrigeration architectures (possibly using capillary action, magnetic separation, or entirely different cooling cycles) or must operate without active refrigeration, relying solely on passive radiative cooling.