I also forgot, well I was curious so I googled, but there is carbon in our asteroid belt, the outer part. I was going to suggest use it for an earlier form of power than the reactor and have the reactor be T6, but you're already getting hydrogen at this point. Then I thought about the drones, Carbon Nanotubes is about to replace silicon in computing, and motherboards can be made of Polycarbonate material, so a Drone plant/facility/station could use Chips+Iron+CarbonMaterial. You could use these materials that would require circuitry like Satellites. I don't think a 3 would be that much of an issue if it's the step to get drones or in the manufacturing of them. Where drones would just not require a space next to the source they're collecting from.