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Hehehe Step by step, first they will start with the most affordable challenges to give time to the evolution of technology. For the construction of a colony ships we will need a cheap way to take tons of materials through the atmosphere.

We need a base on the Moon to transfer materials to and from the asteroid belt until we can get artificial gravity working and build a permanent station on the belt.

Yes I agree. That would be an efficient way to get enough resources to address the colonization of other planetary systems.