Alternative Radioisotope Power Generation Task (ARPG-STUDY)

ARPG is a task to develop a project plan outlining the design, manufacture, assembly, and testing of the Heat Source Agnostic Stirling Generator (SG) Testbed and associated multi-convertor controller.  Several options for radioisotope power sources may be available to future space missions, therefore a Stirling generator design that can accommodate multiple heat sources is attractive.  Two heat source options are the European Large Heat Source (ELHS), fueled by americium-241, and the General Purpose Heat Source (GPHS) fueled by plutonium-238, among other possible heat sources.  The Heat Source Agnostic SG Testbed design will include a trade study to select a Stirling convertor, optimization of the convertor operating point to achieve maximum output power, thermal and structural modeling to analyze multiple environments, and consider radioisotope fueling requirements to achieve a realistic generator assembly process. It will include development of a multi-convertor controller. Some primary functions of the controller are AC-DC power conversion and regulation of the power provided to the spacecraft.  Notable features of the design will be a centrally located heat source that is radiantly coupled to the hot ends of the Stirling convertors, dual-opposed pairs of Stirling convertors, and passive cooling via a radiator housing.  Assembly and integration will occur in the Stirling Research Laboratory at NASA's Glenn Research Center and leverage the experience gained from assembling and testing previous Stirling Generator Testbeds.  The notional testing campaign will include a baseline operation test, a performance map, thermal loss testing to characterize the insulation package, redundancy testing to simulate a failed convertor pair, thermal vacuum testing, Radioisotope Power Systems System Integration Laboratory (RSIL) testing, and random vibration testing.  

The major advantage of the Heat Source Agnostic SG Testbed is the ability to mature a Stirling generator design without committing to a specific heat source.  While it is ideal to have certainty of the heat source isotope to further optimize a Stirling generator, the flexible design of the Heat Source Agnostic SG Testbed will be able to achieve many objectives and serve multiple mission profiles without re-designing the system.  Additionally, maturing both the Stirling generator and the multi-convertor controller in parallel will ensure that all parts of the designs integrate seamlessly.  Testing the Heat Source Agnostic SG Testbed in a laboratory environment will be simple since the electronic heat source will be designed to operate at a variety of power levels and therefore, will be able to easily simulate multiple radioisotope sources, even within the same test.  In addition to simulating multiple radioisotopes, different output power levels can be tested to demonstrate various mission profiles.

This is a mature technology (TRL 7+) — the realistic path in is usually NASA's Technology Transfer Program: licensing an existing NASA patent, or a Space Act Agreement to use NASA facilities/expertise directly. NASA also runs a startup licensing program with no upfront fee for companies formed to commercialize a specific NASA technology.

None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.