End of R&D tree interplanetary engine.

[Dooz]

So after the nuclear engine changed alot it overheats and it consumes more fuel like it takes a 2m half tank with 1 nuke it nearly burns all of that fuel just to get to minmus also the payload was about 8 tons.

so for a end game engine we could have like a VASMIR.

VASMIRS need Lots power like a crazy amount but have a high specific impulse and cost alot alot of money.

for powering them we could have nuclear reactor again end game tech and powered by uranium, uranium is a very expensive resource so the only way to really get it is to mine it from the mun or minmus, and construct the VASMIR powered craft in orbit around the mun or minmus.

Just an idea.

[Frozen_Heart]

Well nuclear engines are meant to fill this role but due to having to remain balanced with chemical engines they can't function anyway near how they could IRL.

Personally I would rather they were balanced by tech tree location and cost rather than by stats.

[worir4]

I think that nuke engines should have some sort of limitation such as maybe requiring ore to run for the reactor. this would require people to have a well established ore mining technique so that kerbals can go interplanetary. (Something equivalent to Moon refueling for RL manned Mars plans).