A goal of extending civilization into orbit in the near-enough future... 15 to 30 year time frame, perhaps, the way things are going... requires a transportation system to match the task. It would have to be able to function long term without significant use of non-renewable fossil fuels, petrochemicals which will be needed increasingly desperately in the future, even more for materials synthesis than for energy.

Instead of launching an occasional spacecraft to lift a large amount of materials and people to orbit, consider a transportation system that delivers an almost continuous stream of payload to orbit from the ground. A small payload delivered continuously every minute, accumulates a very large delivered payload quickly by operating for a few days. An all-electric transportation system will be powered by some of the very solar power satellites it enables built in GEO, thus able to continue transporting goods and people to high earth orbit on into the future without consuming precious petrochemicals as energy sources.

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