Magnetic Droplet Radiator for CubeSat Heat Rejection

High-power CubeSats hold the potential to support advanced mission architectures by offering enhanced capabilities in a compact form factor. However, limitations in existing heat rejection technologies are expected to impose significant constraints on thermal management as power budgets continue to increase. This paper introduces the magnetic droplet radiator (MDR) as a low-mass, high-power alternative to state-of-the-art heat rejection systems. The design trade space of the MDR is explored by addressing relevant material compatibility, thermal performance, magnetic collection, and environmental processes. Results show that a maximum heat rejection rate of 450 W can be achieved with a 0.9 kg, 2-m-long droplet sheet requiring less than 480 mW of power. The specific mass and mass-to-heat ratio of the radiator can be as low as [Formula: see text] and 0.67 kg/kW, respectively, depending on the tradeoff between mass, power consumption, and maximum allowable slew rate. Unlike traditional liquid droplet radiators, the magnetic collection system is robust to perturbations caused by atmospheric drag, solar radiation pressure, axial thrust, and 15 mrad/s ground-tracking slew rates across a wide range of designs. Together, these results position the MDR as a light and effective alternative to existing deployable radiators, facilitating the implementation of high-power small-satellite architectures.