[ThrustVectoring]

Nuclear fission is relatively straightforward so long as you either don't know or don't care about the health risks of radiation. It's just a pile of spicy rocks at the end of the day.

Fusion, on the other hand, requires you to get center-of-sun temperatures and pressures going on to work properly. That usually requires either extremely difficult engineering processes or a fission bomb (and more precise engineering calculations but they're actually reasonably solvable).

[alright2565]

I don't know exactly what he's doing, but fusion is pretty easy to do: https://www.instructables.com/Build-A-Fusion-Reactor/

[whatshisface]

I don't know about easy, but hundreds of people have accomplished this as a hobby project using the Farnsworth design, including a handful of very disciplined teenagers.

[jmopp]

I always thought fusion was easier than fission, since all* you really need is water and electricity — the problem being that it's currently impossible to get more energy than what you put in

* I am eliding over the fact that building a Farnsworth fusor is still a challenge, but less of a challenge than sourcing, purifying, and enriching uranium certainly.

[Retric]

If you just want any reactions then fission is still way easier, you get more fission from a random bit of uranium ore or in some cases even a banana than from a fusor.

Nuclear fission includes radiative decay, what makes a nuclear reactor rather than a bomb or pile of rock is becoming self sustaining where the reaction is driving the reaction. Fusor’s don’t get there, ITER will as the energy from fusion is driving more fusion reactions.

It’s the difference between rotting wood and a fire.