Right now, there are dozens of theoretical proposals for how humans could eventually populate Mars (or the Moon), each as crazy as the next: Space elevator. Inflatables. Giant 3D printer. But there's something wonderful about watching these zany concepts emerge, each with its own unique logic. The latest? A plan to create cave-like dwellings for the one-way astronauts aboard Mars One.

Mars One, if you'll remember, is the Dutch non-profit that made news this year when it put out a call for applications for potential astronauts interested in embarking on a long, one-way journey to the Red Planet. Back in January, Mars One's pitch involved a series of nondescript "pods" that seemed to perch on the surface of the planet. One of the problems with building dwellings on the surface of Mars, though, is that it's wanting for a magnetosphere—and thus, an atmosphere. Part of the challenge of "terraforming" the planet will be building up a new atmosphere.

Or, we could just go underground. That's the concept behind this plan by Russian architects ZA. Here's the bare bones version: A series of robots—equipped with the ability to dig—would identify weak areas in the Martian soil and carve them out. Then, using a process similar to that of structural 3D printing, these robots would "print" interior structures using the leftover basalt—the most common soil on Mars. "This material is already in use in the aerospace and automotive industries," architect Arina Ageeva told Dezeen. "It is stronger and lighter than steel, easier to operate, fireproof and it does not corrode."


As our buds at io9 pointed out this weekend, it's more than a little far-fetched. At the same time, it does build on technology that's developing on Earth. For example, there's Enrico Dini's decade-old effort to develop the first structural 3D printer, the D-Shape. Dini's printer uses a mixture of cement and liquids, superheated to seal the concoction in place. Likewise, the Mars One robot would use solar power to super-heat basalt—volcanic rock—until it became lava-like liquid. When cool, its form would be permanent.

This spring, the European Space Agency—an organization that's far more likely to actually reach the Red Planet—revealed a conceptual study that's not dissimilar from this proposal. Developed in partnership with the architects Norman Foster and Partners, the project studied the feasibility of lugging an army of 3D printers to the Moon, where they could be used to print shelters for the first semi-permanent inhabitants.


Of course, we're a long ways off from either of these ideas being plausible. For one thing, the weight of these printers would be prohibitive. But what does make sense? Taking the weight of conventional materials out of the equation. The precious tons saved from not shuttling steel habitats from Earth to space is the crucial insight here. Barring our ability to seek out natural saves on the surface of Mars, structural 3D printing might just be our best bet. [Dezeen via io9]