how are “nuclear powered” submarines and space probes powered?

Question

In other words, where do “nuclear powered” vehicles get their power from?

I imagine it’s not from fusion or fission, nor can it involve getting water to turn to steam, an in many other types of power generation.

So how does it work?

EDIT: it seems that nuclear submarines actually do use fission, so I’m switching my question to only focus on space vehicle power generation.

In: 3

Answer 1

These two things are totally different.

Nuclear submarines have a small nuclear reactor inside a submarine, it makes electric power with a steam turbine, and everything runs on electricity.

A space probe uses a radioactive thermal generator. The radioactive stuff generates heat and the heat is converted into electricity using the Thermoelectric effect. No moving parts.