Those aren't "reactors". They're just lumps of plutonium that are decaying naturally and producing heat. A reactor has to be able to control a fission reactio

Those aren't "reactors". They're just lumps of plutonium that are decaying naturally and producing heat. A reactor has to be able to control a fission reaction; these can't. https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...