3D-Printed Lego-Like Blocks Can Be Assembled by Robots into Spaceships

Not too long ago, a couple of MIT scientists asked themselves a lofty question: "Can you 3-D print an airplane?" It didn't take long for them to realize that 3D printing anything on that scale was impractical. But 3D-printing thousands of small, Lego-like building blocks? That could work.