I’ve spent a lot of time thinking and writing about a human presence on Mars, including terraforming and utilization of asteroids for mining and manufacturing in space. There’s more here.

The fundamental premise of all my writing is that we can utilize resources in space, outside Earth’s enormous gravity well, to minimize the amount of mass that has to go between Earth’s surface and orbit. I’ve come to realize that the Moon is a resource I’ve been overlooking.

The Moon’s gravity well is far shallower than Earth’s. Add the fact that there’s no atmospheric friction to be overcome and the Moon becomes a desirable location for initial access to raw materials to build the space infrastructure. Bringing construction materials up from Earth is very expensive. Getting materials from the Moon is very inexpensive in comparison.

Consider building a factory at the Earth-Moon L4 or L5 Lagrangian point. If there is mining on the Moon, raw materials could be sent to the Lx point for smelting and construction. If a smelter and a factory could be built on the Moon to make construction components (e.g., steel beams), the total weight sent to the Lx point would be much smaller. This would require moving at least some components from Earth to Moon, but once a minimal factory was operational on the Moon, the remainder could be produced locally and launched to the Lx point using the EML catapult. This could allow construction of a manufacturing complex in space.

NASA ‘s Artemis Project plans a series of journeys to the Moon for science and as a gateway to Mars. This is an opportunity to begin to build an industrial capability in space. We should take it.