Hydrogen fusion

Hydrogen fusion reactors are the main source of power generation in most modern technology. As raw, primordial hydrogen is plentiful in the universe, either in the atmosphere of most planets or in vast clouds in space, the chance of running out of fuel has become nearly non-existent.

While free natural hydrogen can easily be harvested by any spacecraft equipped with a hydrogen trawl, this technique inevitably results in impure fuel mixed with other gasses and various other impurities which are detrimental to a reactor's performance. Therefore, hydrogen gathering, refining and processing has become a vast and lucrative industry.