@bascule@mas.to I like to keep in mind that a uranium-based fission reactor just happened naturally through erosion and sedimentary buildup, millions of years ago in Africa. Fission is so easy that a self-sustaining reaction happened on its own right here on Earth. And when we decided to build a fission reactor, all we had to do was put enough uranium in a pile and it just happened. That damned Demon Core became a nuclear reaction by accident! But other than a couple experiments and bomb tests, fusion has never happened anywhere in our Solar system except in the core of the Sun, and not once has any of those times been self-sustaining. It's a much harder problem to crack. From what I've heard Helion is the most interesting of these fusion power startups, but even their PR sounds overly ambitious.