[retrocryptid]

but the metric the OP was using was power density. nuke fuels are MUCH more energy dense than hydrocarbon fuels. but putting a reactor on each plane would probably have negative externalities.

but mixing your comment with a few others, maybe a nuke plant on the ground that cracks the co2 in the atmosphere to make carbon neutral hydrocarbon fuel.

[wkat4242]

> but putting a reactor on each plane would probably have negative externalities.

Probably? It would be a disaster every time one crashes, would carry a huge proliferation and terrorism risk. Oof.

In the 50's some countries were that crazy and they even put reactors in space. Two of which crashed and one contaminated a huge area in Canada. Luckily common sense prevailed and these things don't happen anymore. Though nuclear ships still exist, there's only a few icebreakers in the civilian fleet AFAIK.

[asn007]

Correct me if I'm wrong, but I thought we still use RTGs in space on some satellites? Not counting extraterrestrial research, since those are definitely still powered by RTGs