Copper/water heat pipes are made of copper, use water as a working fluid and typically operate in the temperature range of 20 to 150°C. ACT manufactures copper/water heat pipes into two basic geometries: Tubular Heat Pipes and Planar Heat Pipes. The tubular heat pipes typically have outer diameters from 1/16″ (1.5mm) to 1.5″ (38mm). Custom diameters can be manufactured per customer requirements. The planar heat pipes are also called vapor chambers which are used as heat spreaders. Copper/water heat pipes can be combined with other components to form heat transfer assemblies .

Satellites traditionally have been used for performing data collection, transmitting, and receiving roles, leaving the data processing/computing to ground stations. As the data volume continues to increase, in-situ computing is increasingly required to minimize latency and maximize reaction speed. However, adding computing onboard satellites creates new thermal management challenges.

Copper-water heat pipes are often used for electronics cooling on Earth and offer excellent performance for short-distance, high heat flux heat transport, but they have limited flight heritage in space. Copper-water heat pipes operate in a slightly higher temperature range than aluminum-ammonia heat pipes; which makes them ideal for operation closer to the electronics in the satellite thermal network. The water working fluid combined with a sintered wick structure is able to handle the higher heat fluxes from electronics chips that are often too high to be handled by conventional ammonia CCHPs. Additionally, water is non-toxic, which is a benefit for ground testing and shipping concerns. In summary, copper-water heat pipes can transport more power, delivered at much higher power densities, and at higher temperatures than aluminum-ammonia heat pipes traditionally used for satellite thermal control.