You've just been tasked with building something enormous in space. How do you do it? Send up an army of spaceships with all the necessary building materials? Every additional pound of material will run you about $9,000 to $40,000, according to Techcrunch. Forget that.
Make alliances with friendly builder aliens? First, we'd have to find them, then, we'd have to trust them not to lay eggs in our chest cavities. Pass.
So what's a space architect to do? Print the structures, of course.