There have been arguments made that building industry on Luna from the small amount of stuff that can be launched with today’s launch systems and today’s budgets would take too long to generate any return on investment. This would be a reasonable argument if there were some alternative that was a credible way of opening up the industrial use of raw materials in space for profit in some faster way.
Some say that there must be a better transportation system before building an industrial base on Luna.  Donald Goldsmith claims a bare minimum of a million tons is needed for a lunar colony. This is what people come up with by insisting ditches be dug by astronauts in space suits using a typical garden shovel variant that was especially designed to make it light in weight. This type of argument does not hold against a lunar colony in which remotely operated equipment is used to set up an electrical distribution system, establish temperature controlled pressure vessels as shelters, extract oxygen, and set up the foundational infrastructure for resource recycling before any humans arrive. Using remotely operated equipment to augment its own ability before getting to direct profit making activities is something like primitive people first making tools out of sticks and stones before making metal working equipment. This sort of thing could stretch out quite a few years, but what is the alternative for a space program? The space station generates various technical information, but has no plan to ever make a financial return. Things that never happen rarely happen before things that take a long time to happen. Waiting for better launch technology has already gotten us the space shuttle which does not seem to be cheaper than former systems. There have been too many schemes for cheaper transportation that did not pay out. Don’t sit on your hands and wait for any more. Develop the scram jets at a modest rate of expenditure, but don’t wait for them before starting a remotely controlled industrial base on Luna. Bet on both horses.
Waiting for remotely operated equipment to go through capacity doubling times with each generation having a smaller percentage of stuff shipped from earth may seem tedious to some. It does have the theoretical potential of setting up launch facilities on Luna that would require only maintenance, electricity, and locally produced rockets weighing 1% of the cargo that is launched to orbit. (See the first mass driver.) There is an exponential factor in the expansion of lunar industry but there are limits imposed by the limited ability to control things remotely from Earth and the limited ability to supply the things that at any particular time still can not be made on Luna. There is a limit to the amount that start up can be hurried by increased transportation of stuff. It takes time to learn how to do things in the lunar way. Once the big brother to Lunarpedia for engineers is up to useable size, things on Luna should start hopping.
First Luna can supply solar cells, station keeping motors, station keeping fuel, and antenna dishes to earth satellites. Later Luna can supply the stuff for solar power satellites. Later yet Luna can supply the stuff for true orbiting space ports.   Then people will be able to emigrate from Earth as fast as space habitats can be built from lunar materials. It may take a hundred years or more, but it will not get done if we limit ourselves to the things that can be accomplished in a permanently manned space station.
- Donald Goldsmith, Voyage to the Milky Way: the Future of Space Exploration. ©1999 by TV Books, L.L.C.
- Donald Kingsbury and Roger Arnold, “THE SPACEPORT” article in Analog SF, New York, November & December 1979.