SBIR-STTR Award

As NASA envisions to develop higher power Hall effect thrusters for large payload (or even crew member) transportation, thermal management becomes a bottleneck. In response to NASA technology roadmap “heat rejection system for in-space propulsion” (TA 2.4.4). Advanced Cooling Technologies, Inc. (ACT) in collaboration with the University of Michigan proposes to develop an innovative thermal management system for hall thrusters utilizing two-phase and passive cooling techniques. Multiple heat pipes constructed with advanced geometry and wick will be integrated strategically in the hall thruster to manage both plasma heating and ohmic heating from magnetic coils. Working fluid and envelope material will be selected based on thermal, electrical and magnetic properties. A proof-of-concept prototype will be fabricated and its thermal performance under the influence of magnetic and electrical fields will be experimentally characterized. A full-scale hall thruster with two-phase cooling system will be designed and its SWaP benefits will be analyzed jointly by ACT and the collaborator. Anticipated

Benefits:
The proposed hall thruster cooling system is fully-passive, lightweight and highly reliable. This will allow NASA to develop more capable and longer life electric propulsion technologies for future deep space robotic and human exploration missions beyond LEO. Example missions are Psyche, Double Asteroid Redirection Test (DART), CAESAR, and Lunar Orbital Platform Gateway (LOP-G). The proposed two-phase hall thruster cooling system will enable smaller, lighter and higher specific impulse hall thruster designs, which will benefit many commercial and military satellites, including CubeSats and SmallSats.

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. nbsp;Based on FEA, ACTrsquo;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.