3D printers could be used to help construct lunar bases with materials taken from the Moon itself. The European Space Agency (ESA) is collaborating with architects Foster + Partners to conduct research into the construction technique, and has "confirmed the basic concept." That concept involves mixing lunar material with magnesium oxide to form the base substance, then applying a binding salt that solidifies the material; inserting the printer's nozzle beneath the moon's surface allows for printing in a vacuum.
via The Verge - All Posts http://www.theverge.com/2013/2/1/3940004/3d-printed-lunar-bases