Abstract: A plenum in combination with a heat exchange panel and a panel structure having a large number of closely spaced orifices of equal size. The plenum area relative to that of the orifice area is such that a pressure head in the plenum is maintained to provide a constant flow of heat exchange medium from the plenum through the orifices to the heat exchange panel.

Abstract: A spacecraft modular system with two components of a cooling system, one in each replacement hardware module and one in the satellite station, with a coupling means in the replacement module in the form of heat sink which collects heat from the heat generating hardware in the replacement module. The heat sink incorporates heat sink fins which interdigitize with coolant tubes in the satellite coolant system and make a mechanical interface with the fins in response to the satellite coolant system pressure for a thermally efficient heat exchange from the replacement module to the satellite coolant system. In another embodiment, replacement module coolant tubes interdigitize directly with the satellite coolant tubes in a fluid pressure responsive thermally efficient mechanical contact to provide a fluid-to-fluid mechanical coupling.