For radiative cooling using aluminum, per 1000 watts at 300 kelvin: ~2.4m^2 area, ~4.8 liters volume, ~13kg weight. So a Starship (150k kg, re-usable) could carry about a megawatt of radiators per launch to LEO.
We are jumping pretty far ahead for a planet that can barely put two humans up there, but it is a great deal of my scifi dreams in one technology tree so I'll happily watch them try.
And aluminum is abundant in the lunar crust.