Multi-Evaporator Heat Pipe Network for Cryogenic Sensor Cooling

Current thermal management systems for satellite infrared detectors employ heat pipe thermal diodes or thermal switches to couple primary and redundant mechanical cryocoolers to just a single sensor. With today's trend toward more but smaller sensors per satellite, these systems can become quite large, heavy, power hungry and expensive. Our innovation allows many sensors to be cooled with just one heat pipe circuit and a single cryocooler. For redundancy, a second cryocooler can be coupled to the same sensor heat pipe circuit. Thus, no more than two cryocoolers are needed to cool many sensors. The resulting scale advantages that accompany the use of larger capacity cryocoolers yields important system benefits, including reduced overall sensor system size, cooler weight, electric power consumption, and cost. The ability to cool several distributed sensors using one simple heat pipe circuit is made possible with a modified monogroove heat pipe design.Utilizing a single self-priming groove configuration with separate liquid and vapor lines, many evaporators can be spliced into a single network, similar to an electrical or thermal bus. While highly innovative, technical risk is reduced because of extensive previous ground and flight test data relevant to this design. Thermal control of many sensors on a single satellite uslng multievaporator heat pipe networks can replace more complex and costly systems currently used that rely on single or redundant cryocoolers to cool individual sensors. Applications include IR and gamma sensing spacecraft, sensors for traffic control, cryogenic filters for advanced cellular phone networks and thermal imaging surveillance systems.