Design and fabrication of the Martian habitat prototype, WATER

This research focuses on the design of a scaled prototype for a Martian habitat on Earth. On Mars each structure has to withstand an outward pressure that is several orders of magnitude greater than conventional structural loads due to gravity and environmental loading on Earth. Therefore, the structure will be mainly subjected to tensile stresses instead of the compression induced in Earth-bound structures under gravity loading. Consequently, this research focuses on inflatable structures as main architectural solutions for designing extraplanetary habitats. The project arose from the vision of using trees as conceptual structures for designing shelters for humans on another planet. The tree is chosen by its ability to extract water from its roots, that is a vital resource for life, and spread it, along its branches, to the exterior leaves. On Mars water is available as ice that can be extracted from the substrate of the local regolith. The Water shielded Architectural Tree for Extraplanetary Resiliency (WATER) project has been algorithmic-based designed in order to be analyzed and optimized from an architectural and structural point of view. The number of branches as well as their final shape are chosen by their intrinsic feature of containing a thick layer of flowing water, that helps balancing the internal pressurization load of the habitat and shielding against cosmic radiations. The final configuration of the WATER prototype is composed by an inflatable outer membrane that is anchored to the base along its perimeter and through the internal branch structure that works in tension, as on Mars. The branches have different diameters at each iteration like a real tree. Therefore, a custom computational study was required to automatize their entire design process. The scaled prototype has been realized using a combination of different digital fabrication techniques, such as 3D printing, Computer Numerical Controlled (CNC) drag knife and pen. In detail, the CNC pen and CNC drag knife were used to mark and cut the inflatable membrane in clear vinyl of the outer structure. Instead, the 3D printing has been used to fabricate the custom made joints for each iteration of branches. The branches have been cut out of transparent polycarbonate tubes. The entire structure has been fixed on a plywood box and connected to an air compressor for enabling the inflation and simulate the Mars environment.