3-D Printers And Robotic Arms: How One Startup Plans To Build Off-World Colonies

This space-optimized wrench was 3-D printed on the International Space Station. In the coming decades, humans will begin to colonize the "final frontier." Private rocket companies -- including Elon Musk's SpaceX and Jeff Bezos' Blue Origin -- are already building vehicles to ferry settlers to outer space. But what happens once these early colonists step off their ships and onto the hostile surface of Mars or the Moon? When history's pilgrims and pioneers arrived in a new territory, they used the land's natural resources to build their settlements.