>I think the issue with Stirling Engines is the fact that they have moving parts that could wear and break down. In NASA's ASRG design there is a stirling gene

>I think the issue with Stirling Engines is the fact that they have moving parts that could wear and break down. In NASA's ASRG design there is a stirling generator with only has one moving part: a free piston moving inside a coil, cushioned by the working gas. Wear and tear should be minimal, even for a multi-decade mission. https://solarsystem.nasa.gov/rps/docs/ASRGfacts2_10rev3_21.pdf https://solarsystem.nasa.gov/rps/docs/ASRGfacts2_10rev3_21.p... (page 2)