Toronto team qualifies phase-change heat sink for small satellites

(SpaceEnergy) University of Toronto researchers have qualified a phase-change-material heat sink for small satellites, targeting thermal control of increasingly high-power spacecraft hardware.

The work was driven by an upcoming Space Flight Laboratory mission requiring passive thermal buffering for a high-power payload. Phase Change Material (PCM) heat sinks absorb transient heat loads as latent heat during melting, limiting peak temperatures and reducing required radiator area.

Researchers developed and experimentally validated a simplified thermal model, then produced two hardware iterations: a prototype using n-octadecane for a 50W optical terminal and a qualification model using n-docosane for a 36W transmitter.

Vacuum testing showed model predictions within 0.5°C of measured thermal performance. Tests in multiple orientations produced only 0.6°C variation, helping bound expected behaviour in microgravity.

The qualification model also passed helium leak, proof and burst-pressure testing, achieving a burst factor of 7.3, and survived an 18.2g-rms random-vibration profile without problematic coupling to the spacecraft structure.

The researchers said the framework provides a repeatable route to lower-cost, mission-specific thermal control for high-power small-satellite hardware.