[drzaiusapelord]

I was referring to the new stirling engine RTG. According to wikipedia, NASA doesn't see it being used in a mission for another decade or two due to further testing and certification.

I wasn't aware solar was so heavy. Thanks for the info.

[mikeash]

Inverse square is a harsh mistress. With only 4% the insolation at Jupiter as you get at Earth, you need a lot of panels.

Stirling RTGs sound very interesting but I'd be really worried about reliability. Definitely needs lots of work and testing to be confident in it!