RTG: http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_gen... Basically instead of ha

RTG: http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_gen... Basically instead of having a big complicated nuclear reactor, you just throw some radioactive material in a package, let it decay, and generate electricity off the heat. It's mechanically much more simple and has the bonus of not involving critical masses of radioactive material ;) Not very realistic though. Besides the obvious issues of carrying around lumps of plutonium, they're rather bulky, and disposal is a pretty major problem.