In September 2015, NASA announced the winners of its 3-D Printed Habitat Challenge. The winning submission titled 'Mars Ice House' by Clouds Architecture Office / SEArch proposed a 3D-printed double ice shell surrounding a lander module core. Two European teams were awarded runner up prizes. The contenders explored many possibilities for materials, with one suggesting separately refining iron and silica from the Martian dust and using the iron to make a lattice-work filled in with silica panels. There were 30 finalists selected from an initial pool of 165 entries in the habitat challenge. The second-place winner proposed the printing robots build a shield out of in-situ materials around inflatable modules.
