NASA SBIR 2003 Solicitation


PROPOSAL NUMBER: 03- II F7.01-8219
SUBTOPIC TITLE: High Power Electric Propulsion For Human Missions
PROPOSAL TITLE: Thermal Management of Superconducting Electromagnets in VASIMR Thrusters

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
William Baschnagel
Etna Rd., P.O. Box 71
Hanover, NH 03755-0071
U.S. Citizen or Legal Resident: Yes

The Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine currently being developed at NASA Johnson is an attractive technology for minimizing transit time and crew harm during future space exploration missions. One of the critical challenges in developing a flight engine is thermal management of the high-temperature, superconducting electromagnets used to constrain and accelerate the plasma. The innovation of the proposed project is a high-capacity turbo-Brayton cryocooler for this application. The cryocooler has heritage in the space-qualified cryocooler that was developed by Creare and installed on the Hubble Space Telescope. Turbo-Brayton cryocoolers are lightweight, compact, efficient, and highly reliable. The technology scales well to high cooling capacities and is simple to integrate with multiple cooling objects; attributes that are particularly beneficial for VASIMR systems. In Phase I, we developed a preliminary design of the thermal management system, addressing key issues regarding the application of turbo-Brayton cooling technology to VASIMR engines. In Phase II, we plan to build and demonstrate a brassboard thermal management system. Phase II is justified by the feasibility demonstrated in Phase I, by the relevance of the project to a development effort at NASA, and by the importance of this technology to NASA's goal of space exploration.

Potential non-NASA commercial applications include cooling systems for high-temperature superconducting magnets in: magnetic resonance machines, AC/DC motors, generators, transformers, fault-current limiters, magnetic separators, transmission lines, and flywheel energy storage systems. Commercial applications for high-capacity cooling technology include commercial orbital transfer vehicles and satellites, as well as cryogenic gas separation, liquefaction, storage, and transportation systems.

This program will result in a thermal management system for high-temperature superconducting magnets that is lightweight, efficient, and simple to integrate. Space applications for the system beyond electric propulsion include other systems requiring a high-capacity cooler, such as cooling systems for: cryogen storage for extraterrestrial exploration missions, extended life orbital transfer vehicles, long-term geosynchronous missions, in-space propellant depots, and for extraterrestrial bases. Terrestrial applications include cooling systems for spaceport cryogen storage and for cryogen transportation systems.