Description: The Harmonia-Radioisotope Power System (RPS) Tipping Point (TP) Project is developing a Stirling Convertor enabled radioisotope power system that utilizes a long lived, thermally constant heat source, Americium-241 (Am-241). The Harmonia-RPS Tipping Point Project will perform an initial technology readiness assessment to establish the technology readiness level (TRL) of a novel Am-241 heat source design. Once determined, technology maturation plans will be developed to improve the TRL of the Am-241 heat source to TRL 5 by project completion. Additionally, the Harmonia-RPS Tipping Point Project will develop an RPS design that will provide heat and power to an Intuitive Machine's lunar lander and enable long-duration access to lunar surface destinations, including survive-the-night capabilities and long mission durations in permanently shadowed regions. The Harmonia-RPS Tipping Point Project will deliver an Electrically heated Stirling Generator (ESG) that is compatible with the Am-241 heat source design to conduct testing in relevant lunar environments, including thermal vacuum (TVAC). Execution of ESG testing in relevant environments will mature the ESG technology to TRL 6 by project completion. Harmonia-class RPS technology directly aligns with the requirements that contribute to Space Technology Mission Directorate (STMD) and NASA's broader science, technology, and exploration objectives. Other important national objectives include the near-term demonstration of Stirling conversion for an RPS, as recommended in a recent Planetary Science Decadal Survey, and the commercial development of space nuclear power systems per Space Policy Directive-6. Compared to the “state of the art," Harmonia will establish an affordable private-sector radioisotope capability, supporting new government and commercial applications.

Benefits: Beyond the NASA missions, the Harmonia-RPS capability has a strong business case due to the significant commercial demand for long lived lunar surface assets. Intuitive Machines (IM) will inform the RPS interface requirements and develop the lander simulator design required to deliver an RPS-enabled IM lander capable of surviving and operating during the lunar night. Blue Origin will be responsible for the power system design and integration of the Stirling convertor into an RPS, making it suitable for integration into any platform. The Harmonia team will develop a transition plan so that the technology can be further developed to a flight qualified Radioisotope Stirling Generator (RSG) system in a future commercial or government mission, from rovers to nodes to crewed applications. Critically, given the long-lived nature of Am-241, lunar surface heat sources can be recycled via interoperability for decades, supporting Artemis sustainability. The target markets for the proposed technology range from equatorial regions to permanently shadowed regions, at a competitive cost.