This proposal envisions a radically new approach to thermal management and electrical power generation onboard spacecrafts. A broad range of satellite sensors for Earth Observation and Science Missions require active cooling in order to reduce the effects of thermal noise, often to cryogenic temperatures. However, the main requirements for cryocoolers in almost any space application – high electrical-to-thermal efficiency, minimal to zero vibrations, miniaturization and high reliability – are not met by any of today’s cryocooling methods. One of the most promising solutions is optical cooling of solids, although the efficiency of current optical cryocooling approaches is relatively low in comparison to mechanical cryocoolers. While this is favorably offset by smaller volume and weight, a different optical cryocooling approach is needed to fully outcompete existing cryocooling technology. The innovation of this proposal is that a significantly higher efficiency appears possible by using direct conversion of solar radiation for the purpose of optical cryocooling, i.e., without the need for an intermediate step of solar-electrical-optical conversion. Moreover, the approach enables a radical inversion of thermal and electrical management onboard spacecraft: instead of first converting solar radiation to electricity for powering the satellite instrumentation and cooler, the proposed approach is to use solar radiation first for optical cooling, followed by the recuperation of waste radiation to generate electrical power. The resulting gain of this approach is not only higher cooling efficiency, but in effect also more efficient generation of electrical power with compact photovoltaic (PV) modules. If successfully implemented, this approach opens the way to miniature, efficient, truly vibration-free, reliable combined cooler-electrical power generators. As such, the approach is a key enabler of future compact space systems for generating superior quality spaceborn data.
