It would be very hard and very expensive to build a space colony that was self-sufficient, instead of requiring constant supplies from Earth. In fact, it would

It would be very hard and very expensive to build a space colony that was self-sufficient, instead of requiring constant supplies from Earth. In fact, it would be very hard and very expensive to build a self-sufficient society on Earth which was up-to-date with modern technology. The range of products and materials required is vast, and the manufacturing of certain state-of-the-art products, such as the most advanced integrated circuits, has been centralized in only a few locations. It would probably also require a change of culture, away from treating information as property and/or trade secrets in favour of open-hardware with shared designs. Designs would be shared and manufacturing decentralised, to improve robustness.