Lockheed Martin has just finished the final series of quality control tests for an enormous titanium dome meant to serve as caps for satellite fuel tanks. It's not just any ordinary dome, though: the enormous component measures four feet in diameter and is the company's biggest 3D-printed space component to date. Its previous largest qualified space part is an electronics enclosure that's around the size of a toaster. This dome is large enough to seal fuel tanks bigger than humans and, according to Lockheed Martin, big enough to hold 74.4 gallons of coffee or 530 donuts. Glazed, of course.