Review on phase change materials for spacecraft avionics thermal management

Phase Change Materials (PCMs) have played a significant role in the effective passive thermal management of spacecraft electronic components. With increasing space activities anticipated in future, efficient and reliable thermal management strategies are being developed, where PCMs are poised to play a vital role. PCMs help in the dissipation of large heat flux levels and find their applications in highly transient environments where sudden surge of power needs rapid dissipation. Utilizing the latent heat of fusion, PCMs can be reliably used without the need for additional pumping power requirement for its operation, while ensuring that the surface temperature does not exceed beyond a certain limit, depending upon the phase transition temperature. Although PCMs offer several benefits, there widespread adoption is limited to an extent, owing to their low inherent thermal conductivity. To this end, several methods have been developed to address this challenge which limits PCM's application in avionics thermal management. This review article provides a comprehensive overview of the historical development of PCM-based thermal management solutions for avionics thermal management, and how this research is expected to evolve given rapid advancements in material science and engineering, chemistry involving PCMs, filler material which could be additively manufactured. The review article provides details on the efforts of different space programs where PCMs have been employed in the past. Furthermore, PCM's utility in power generation is illustrated where it can be coupled with photovoltaics and thermoelectric generators to provide stable power. Towards the end, different PCMs and filler material options have been summarized along with their thermal properties, and concluding remarks have been presented on the studies needed to be carried out for widespread adoption of PCMs in space programs' avionics thermal management segments.