> One of the large problems to solve, as I understand it, is containment. No need for containment on the sun. Containment, in the context of fusion, doesn't re

> One of the large problems to solve, as I understand it, is containment. No need for containment on the sun. Containment, in the context of fusion, doesn't refer to preventing the reaction from running rampant. It refers to keeping the reactants in a small confined space so the reaction can continue at all. The sun achieves this containment through the least efficient means: it's gigantic mass means that the reactants are forced together by the force of gravity. Plus, the shear quantity of superhot plasma helps ensure that energetic particles have an excellent chance to hit another core, keeping the reaction going. Note that the solar core, where the vast majority of solar fusion happens, is ~0.25 of the sun's radius, so ~25 Earth radii. Quite hard to get the amount of plasma on Earth. The entirety of the Earth doesn't have even a fraction of the Sun's mass, so that is impossible to reproduce. So we need to rely on much more violent forces to achieve a similar level of containment as the Sun.