Phase-Change Material Thermal Management for Extreme Space Environments

Thermal management is essential for the extreme environments of space - vital in order to conduct successful missions, make new discoveries, and push the boundaries of space exploration. Without adequate temperature control systems, astronauts and equipment can be exposed to extreme temperatures that could cause equipment failure, decreased performance, and even risk human life. Thermal control systems come in a range of varieties but include those based on phase-change materials (PCMs), which are passive, reliable and effective, if properly designed. PCMs are particularly attractive due to their unique ability to protect against both hot and cold temperature extremes by absorbing, storing, and releasing thermal energy during temperature cycling, thus maintaining a stable thermal environment. In space, it is essential that the PCM is housed within a suitably robust container - preferably one that allows rapid heat transfer from the heat source to the PCM. Here, we report on key learnings from our team's additive-manufactured (AM) PCM-heat sink, namely the “Matilda” payload, launched to low-Earth orbit on Waratah Seed-1. Specifically, we report on the necessary compromises encountered between the heat transfer benefits resulting from complex thermal conductivity-enhancing structures enabled by AM, and the additional manufacturing challenges resulting from AM.