Feasibility study of a ferrofluid droplet radiator for High-Power CubeSat Applications

Abstract

High-power CubeSats are attracting substantial attention due to their ability to offer augmented capabilities comparable to larger satellites, but with significantly lower cost and mass. As their applications expand, the demand for high-power components also increases, making thermal management essential to the success of the mission. Current power dissipation solutions, such as body-mounted radiators, are limited by the available surface area, rendering them less effective for high-power missions. Recent comparative analysis indicates that state-of-the-art deployable radiators can reject up to 200 W of heat. However, new solutions may soon be needed to overcome this limitation and support high-power missions. This work presents the SmallSat ferrofluid droplet radiator (FDR) as a solution for high-power missions, that offers increased surface area with reduced mass. The FDR operates by ejecting a layer of high-temperature droplets from a micro-meter injector to radiate heat into space. Droplets are then collected by a neodymium magnet positioned at the tip of a deployable boom. A redundant set of pumps is incorporated to maintain the continuous operation of the closed-loop thermodynamic cycle. The FDR combines the heat transport and rejection processes into one system, eliminating the need for the traditional thermal path. While earlier studies have demonstrated the feasibility of this technology in handling significant heat levels for larger satellites, the applicability of this technology to SmallSats heat rejection remains unexplored. This thesis focuses on studying the feasibility of the FDR in the context of high-power CubeSat communication. Communication systems are an essential component of every space mission. However, as power requirements become more stringent, the operation of high-bandwidth telecommunication systems will be constrained by the design of the thermal control system and the environmental challenges. Preliminary results from parametric analysis and design optimization indicate the potential of the FDR to dissipate heat in the range of 100 to 500 W. Additionally, it addresses key challenges of fluid behavior in space and previously encountered issues with the liquid droplet radiators. Further experimental and simulation studies are necessary to investigate the radiative behavior of the radiator and assess its performance under extreme conditions in low Earth orbit. Following this analysis, an optimization of the collector will be conducted. The ultimate goal is to enable small platforms like CubeSats to undertake high-power missions and meet the growing demand for high-quality, faster data transmission rates.