Where to next in the outer solar system? Scientists have big ideas for Pluto, Neptune and Saturn

Oh, cool! Enceladus is high on my personal wish list. And the Orbilander mission seems like a start. (No sample-return, which is bad since life or fossil search methods use microscale lab work to control for abiotic confounds.)

Concerning the RTG problem, maybe pairing up with ESA ? They're developping Americium-based RTG...

We are? We are!

Radioisotope power systems utilising americium-241 as a source of heat have been under development in Europe as part of a European Space Agency funded programme since 2009. The aim is to develop all of the building blocks that would enable Europe to launch and operate deep space and planetary missions in environments where use of solar power or alternative power generation technologies is challenging. Although some technical and policy work activity predate the ESA programme, the maturity of the technology has now reached a level that it can be incorporated in mission studies and roadmaps targeting the period from the mid 2020s onwards.

[ https://link.springer.com/article/10.1007/s11214-019-0623-9 ]