Dr. Behrokh Khoshnevis of the University of Southern California has developed a system for using 3D printing to construct buildings out of concrete. The idea sounds out of this world, and someday it may be – Khoshnevis has proposed using the system for building on the moon. According to TreeHugger’s Lloyd Alter, previous iterations of the system required moving the entire system from building site to building site.
But you don’t have to do that anymore; computers and technology have improved enough that one can envision a mobile robot that just squirts out the concrete where you need it; It is smart enough to figure out where its nozzle is in all three axes. The concrete would be locally made, using sulfur instead of Portland Cement; from the 2005 paper:
Experiments carried out on lunar soil samples returned by Apollo missions revealed that sulfur could be extracted from lunar soil by heating it at moderate temperature (of the order of 1000-1200 degrees C), which can be achieved with standard solar concentrators on the Moon…. Sulfur may offer an alternative to Portland cement as a binder in making concrete for use in lunar construction.