At the moment asteroid mining is one of the best. Quantifies of various rare metals are limited on earth and we have companies working on making asteroid mining a reality.
Earth has laws that prevent certain economic transactions from happening. Various biotech and genetic engineering projects might get outlawed on earth. Human cloning that happens in space stations might make for an interesting story.
There might be nanotech that needs very high precision. Today an electron microscope is effected by a train braking a few kilometers away.
Nanotech could allow you to build cheap very big mirrors that redirect solar energy from one point to another. If you bundle it enough you could have a laser weapon that takes very little time to hit targets. The energy from the mirrors could also be used for electricity generation. On earth but also maybe on Mars.
Earth has laws that prevent certain economic transactions from happening.
Wouldn't it be easier to bribe officials.
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