This week on the RELEVANT podcast, we discussed the coming 3-D printing revolution and how it could change consumerism as we know it. Well, the European Space Agency has even bigger plans for the technology than homemade guns and personalized iPhone cases. It wants to use 3-D printing to build a moon base. And this isn’t just some far-flung Newt Gingrich campaign platform; they’re actually putting some pretty intense research behind finding ways to turn moon rocks into concrete. And with the help of a robotic 3-D printer, engineers believe they can create the shell of a structure that could house future moon colonists. Once there, humanity can finally dedicate the time and resources necessary to unlocking the moon’s deepest mysteries, like “How fast do you think we can get this rover to go?” ...