Point Zero Barge is a facility in orbit just above Gethen’s atmosphere. It serves as a docking station and offloading port for the trawler ships that venture into the atmosphere. The trawlers’ modular cargo bays detach and feed directly into Point Zero’s processing plants, which separate out the gaseous and liquid Nephelium, which are sent to a pipeline, from the solids, which are packed into shipping containers. Point Zero has a space elevator, with the liquid and gas pipelines running alongside, that leads from Point Zero’s position just above the atmosphere all the way up to a short distance from the Knot’s orbital altitude. (This isn’t necessarily close to the Knot all the time, depending on their relative orbits, it’s just to carry the materials farther up from Gethen’s gravity well so they’re easier for ships to transport.) This cargo is then ferried to a processing facility in the Knot’s Docks, which packs them into containers that keep the Nephelium stable for long-haul space flights and loads them into Rocs.