1. Miniature Engineering Systems Group Two-Stage Cryocooler Development for Liquid Hydrogen Systems

2. Technical Objective To develop efficient, compact, reliable, affordable cryocoolers for distributed cooling for liquid hydrogen systems. NASA Advisors: George Haddad and Bill Notardonato (KSC), Tom Tomsik (GRC) Applications: Refrigerated cryogenic transfer line - line chilldown, zero boil- off, in-line propellant densification Distributed cooling for zero boil-off in transfer/transport vessels Cryogenic storage and liquefaction of propellants in future Mars missions

3. Recuperator DC Power Supply Motor/ 2 stage intercooled compressor Intercooler Q rej Motor/ 2 stage intercooled compressor Recuperator Turboalternator Q rej JT expander Load Interface DC Reg- ulator/ Power Suppl y External HX Two Stage Cryocooler Neon RTBC and Helium JT

4. Prior Activities on Efficient, Compact Cryocoolers Phase 0 (completed in June 2002) Developed system concepts for efficient, compact cryocoolers to explore how technology developed for portable refrigeration system can be applied. Developed innovative designs for key, enabling components such as compressor, motor/generator, heat exchanger. Performed preliminary testing for an efficient, compact motor.

5. Phase I: Task 1. System evaluation and design Task 2. Centrifugal compressor: design, fabrication and testing Task 3. Motor/Generator: design, fabrication and testing Task 4. Friction and wear mitigation Statement of Work