Experience in using loop heat pipes to provide thermal control for long-service-life spacecraft

The paper reviews results of using autonomous thermal control equipment based on loop heat pipes within long-service-life spacecraft developed by RSC Energia. Using the example of twenty years of service within the geostationary satellite Yamal-200 and twelve years of service within Rassvet module of the International Space Station, it demonstrates the stability of operation of loop heat pipes and their passive regulation devices when the spacecraft is exposed to varying external heat fluxes. It also provides data on the use of backup active devices for regulating loop heat pipes. It discusses certain special aspects of ground tests on loop heat pipes after their integration into a spacecraft. An analysis is provided of the overall effectiveness of using heat pipes within spacecraft for various applications. Thus, the experience gained in operation of loop heat pipes allows recommending them as autonomous thermal control equipment for heat-generating hardware of future spacecraft.