Rails should serve as conductors.

What the hell kind of engineer would design a 1-wire electric system with (I'm assuming) ground-rods drilled deep into the soil on various planetary bodies to serve as the return path ...

Yet not abuse rails to provide a 3-conductor electric system and thus greatly simplify the distribution of the unlimited power facilitated by the recently developed nuclear power industry?!

edit: This has nothing to do with electric trains. This is only about transmitting power to remote location. I actually enjoy the logistics challenge of fueling trains and believe that fueled trains are the best solution given the unique challenges presented to the crash-landed engineer.