>>7633282The onboard computer was limited, but they had human pilots on board and a radio link.
For big number crunching they could run calculations with the room sized computers on Earth, then radio information to the spacecraft.
That's part of why reusable rockets are only recently becoming a thing. They must have the processing power to be fully autonomous during descent and landing, using their own sensors and processors rather than relying on a ground link.
Similar situation with autonomous cars, drones, and robots.
