After Spaceport America in New Mexico, Foster's work outside Earth is a logical step. But in the case of the Moon, we are not talking about an entertainment, but about a solid state project: the customer is the European Space Agency.
It examines the prospects for the colonization of the Moon: for this, the regions of its poles, where the sun is almost always shining and temperature drops are minimal, are suitable for this, and solar panels will also give maximum efficiency. But with the possible development of an Earth satellite, the delivery or production of building materials on site will become a problem.
Foster's project solves this problem: in a rocket, only a cylindrical container with an inflatable "formwork" is delivered there. After its installation in place, a mixture of lunar soil (regolith) and magnesium oxide is sprayed on it using a 3D printer, and a saline solution acts as the "ink". So that the liquid does not "boil away" under vacuum conditions, it will enter the regolith layer in minimal doses. When "printing" will be obtained material with large cavities, resembling the structure of the bones of birds.
The base project is designed for 4 people, whom such walls can protect from very high and low temperatures, cosmic gamma radiation, small meteorites. Moon dust (which is very dangerous for the respiratory tract) and the required level of thermal insulation remain a problem.
The D-Shape printer was developed by the English company Monolite, which uses it to create sculptures and artificial coral reefs. The current model is capable of "printing" 2 m / h, currently in development - 3.5 m / h. At this pace, building the base will take a week.
Italian engineers Alta SpA and the engineering institute Scuola Superiore Sant'Anna (Pisa) also took part in the preparation of the project. Among other things, they found an inexpensive analogue of regolith necessary for experiments: the basaltic rocks of one of the volcanoes in central Italy coincide in composition with it by 99.8%. Usually terrestrial "regolith" is produced artificially and sold by a kilogram, but in this case such an option would be excessively expensive, since tons of this material are used for experiments (including under vacuum conditions).
