Description: Advanced Cooling Technologies, Inc. (ACT) proposes to develop and mature a lightweight, compact, and highly effective passive two-phase thermal management system (TMS) for extremely high power-density commercial magnetically-shielded Hall thrusters, aiming to enable NASA for its future cislunar and deep space missions. In Phase I, ACT performed a comprehensive heat pipe design trade study and developed two unique three-dimensional alkali metal heat pipe prototypes for 20 kW H9 Hall thrusters. Both heat pipe prototypes outperform the heat transfer requirement obtained in finite-element simulations by up to five times and can operate in any orientation irrespective of the presence or absence of electromagnetic fields. Passive two-phase HPs are integrated with a small hot radiator, being in radiative heat transfer with downstream while a relatively larger cold radiator attached to the back of the H9 Hall thruster, protects the temperature-sensitive components from overheating. Based on FEA, ACT’s innovative passive two-phase TMS could decrease traditional cold radiator of a 20 kW H9 thruster by up to 40% in size and 1 kg in mass. In Phase II, followed by continuing to further optimize and mature the passive two-phase TMS, ACT will integrate its passive two-phase TMS on UMich. H9 Hall thrusters and experimentally measure thrust, efficiency, specific impulse, current oscillation etc. inside a large vacuum chamber. The final deliverable will be a passive two-phase TMS, consisting of down-selected heat pipes, hot and cold radiators.

Benefits: The proposed passive two-phase thermal management system cooling system can effectively remove the waste heat from Hall thrusters to the heat sink. This will allow stability for a long-duration flight operation of high power-density Hall thruster in space. Many NASA programs will be benefited, including deep space Psyche, cis-lunar Gateway, electric propulsion to Mars and Planetary habitat, etc.

High power-density Hall thrusters will be a game-changer in the future spaceflight market. The “plug-and-play” components developed under this program, are adaptable for many commercial Hall thrusters serving in telecommunication and defense applications. SpaceX, Busek, Aerojet Rocketdyne, etc. will be potential customers of this ACT’s passive two-phase thermal management technology.