The building process itself can be very inefficient, and even dangerous. The surface of the Moon, for example, is covered in a fine layer of Moon dust made of sharp, microscopic grains which can slice into an astronaut’s lungs if breathed in too deeply. This moon dust can become electrostatically charged and cling to equipment and spacesuits, which makes building on the Moon like working on a construction site with super-charged asbestos. It is work better suited to robots than humans.