Thermal Management of Superconducting Electromagnets in VASIMR Thrusters

Future manned space exploration missions will require high power electric propulsion. VASIMR thrusters are the most attractive option because they offer short transit times and low propellant usage. A key component in VASIMR thrusters is the cryogenic electromagnets. Cooling systems for the magnets do not currently exist. The innovation of the proposed project is a high-capacity turbo-Brayton cryocooler for thermal management of VASIMR electromagnets. The cryocooler has heritage in the space-qualified unit that was developed by Creare for the Hubble Space Telescope. Turbo-Brayton cryocoolers are ideal for space applications because they are lightweight, compact, efficient, highly reliable and have long maintenance-free lifetimes (>10 years). Furthermore, the technology scales well to high cooling capacities and is inherently simple to integrate with multiple cooling objects; attributes that are particularly beneficial for VASIMR systems. In Phase I we will design thermal management systems for VASIMR thrusters at power levels consistent with near-term flight experiments and future manned space exploration missions. During Phase II, we will demonstrate a prototype thermal management system. In Phase III we will develop the complete thermal management system, integrate the system with a VASIMR thruster, and demonstrate the system through tests in a thermal vacuum chamber.