Gas giant refinery

A gas giant refinery is a series of orbital megastructures that would be suspended in the atmosphere of any gas giant such as Jupiter or Saturn.

Their purpose would be to harvest large amounts of hydrogen / helium or other gases from the planet to prepare the raw elements for transportation elsewhere. The refineries would be floating aerostats and orbital vehicles would collect raw gasses from them to transport to the rest of the solar system to be used as a vital energy source. This process of extracting materials from an unstable planet surface is called planet lifting, whereas extracting materials from a star is called star lifting.

Workers would typically live nearby in habitats and if the operation goes large scale, it can turn into an Industrial Zone typically using a Deep Well for mining. The well could be built around an artificial black hole from a moon that had been stellified. Hydrogen is mined from the atmosphere of the gas giant and directed towards the black hole, forming an accretion disk. Fusion reactions take place within the accretion disk and generate heavy elements which are mined for manufacture into various industrial products, typically controlled by interplanetary corporations. These are used in the place of asteroid and lunar mining operations in regions where elements heavier than helium are scarce. The creation of elements up to iron is exothermic, and produces large amounts of excess energy which can also be collected for use.

Helium-3 and deuterium mined from gas giants would be also used as fuel for spacecraft.

An alternative for mining gas planets would be to turn them into shellworlds. The surface of the shells would extend beyond the gas planets' ferocious winds but still be low enough in their atmospheres to be protected from meteorites. Graphene tethers could be connected to the interior surfaces of those shells worlds and which descend deep down into the atmosphere. We could build vast, kilometers-long mega-skyscrapers called Atlas Towers which are attached to those tethers, also functioning as habitats and refineries. Materials extracted such as methane, ammonia, nitrogen and water could be used to create artificial atmospheres, provide nutrients for plants, and provide water for life, to create cities. These cities could either be built into the tethered Atlas Towers, or dangle from the interior ceiling of the shellworld and be called Chandelier Cities.