Printing a Moon BaseThe European Space Agency (ESA) announced January 31 that it is looking into building a moon base (pictured in an artist's conception) using a technique called 3-D printing.It probably won't be as easy as whipping out a printer, hooking it to a computer, and pressing "print," but using lunar soils as the basis for actual building blocks could be a possibility."Terrestrial 3-D printing technology has produced entire structures," said Laurent Pambaguian, head of the project for ESA, in a statement.On Earth, 3-D printing, also known as additive manufacturing, produces a three-dimensional object from a digital file. The computer takes cross-sectional slices of the structure to be printed and sends it to the 3-D printer. The printer bonds liquid or powder materials in the shape of each slice, gradually building up the structure. (Watch how future astronauts could print tools in space.)The ESA and its industrial partners have already manufactured a 1.7 ton (1.5 tonne) honeycombed building block to demonstrate what future construction materials would look like.—Jane J. Lee

Illustration courtesy ESA/Foster + Partners