Humans can build large sealed cities on the Earth-facing side of the Moon using solar-propelled remote-controlled "drone" technology. The response time is only

Humans can build large sealed cities on the Earth-facing side of the Moon using solar-propelled remote-controlled "drone" technology. The response time is only about 1 or 2 seconds so the human operators on Earth wouldn't need the equipment to have much of its own AI (unlike later on when humans repeat the process on Mars). Once enough such specialized machinery is on the Moon, entire "cities" the size of an apartment building could be built, funded in the same way Ordos in China was. The hard part would be experimenting with different biochemical processes afterwards in each city so one of them could provide enough oxygen, water, and food for humans who'd arrive much later on.