Statement of Objectives (SOO) Summary

This is a Statement of Objectives for Topic 3 under NASA's NextSTEP-3 Appendix A, detailing requirements for the design, fabrication, and testing of a high-efficiency Radioisotope Stirling Generator (RSG) for lunar and Mars missions. NASA seeks commercially viable solutions for advanced power conversion systems that reduce fuel requirements by a factor of three to four compared to current RPS technologies while supporting extended operational lifetimes in extreme environments. The effort emphasizes developing scalable power system architectures capable of operating in permanently shadowed regions and extended lunar nights, with designs providing 40-50% power output upon single failure.

The contract encompasses four primary objectives: (1) producing a system design capable of supporting Moon and Mars missions with survival heat and power for landers and rovers; (2) demonstrating advancement from Technology Readiness Level 3-4 to 5-6 through subsystem and system-level demonstrations with an electrically heated prototype operating on a simulated spacecraft bus; (3) maturing interfaces for rejected heat delivery and documenting extensibility to higher power levels; and (4) developing draft regulatory processes and schedules for the selected fuel type. Key Performance Parameters include demonstrating 50-150 We DC power output (extensible to 300 We), achieving minimum 20% system efficiency with 1 W/kg power density and 5-year design life (extensible to 10 years), rejecting 40-50% of converter heat for host spacecraft survival, and successful operation in simulated environments. The scope is limited to Americium 241 fuel designs and excludes extraneous fabrication, flight hardware, destructive testing, and alternative fuel types. Deliverables include design reviews, hardware prototypes, technical reports, test documentation, extensibility assessments, regulatory pathway documentation, and government insight activities such as technical interchanges and monthly status meetings.