by Bill Otwell, Otwell Associates Architects
NASA just held a design competition for prototype Mars habitats.
Two of the four finalists used regolith, the layer of dust and rocks that covers the surface of a planet. It is basically Martian adobe. The inspiration for this concept is adobe construction here on Earth, where about 30 percent of the population lives in earth-made houses.
Today, architects are using adobe as a very important component of sustainable design. The obvious advantage of using on-site material on Mars (instead of sending up a load of 2x4s and concrete blocks on a rocket) is also a sustainable approach on Earth. Onsite production of adobe eliminates transportation cost and most material cost.
A small percentage of the mix is asphalt emulsion to waterproof adobe blocks (1 to 9 gallons of water, added to the soil on-site). Once the material is mixed into mud and placed in forms, the curing is provided by sunlight, a solar powered manufacturing process.
Once the blocks are cured, they are laid into a wall with the same mud for mortar. On Mars, the material will most likely be printed in 3D. Exterior surfaces require some ridged foam insulation and cement stucco or other siding material. Interior finishes can be adobe plaster without the asphalt, paint or even exposed adobe. Walls are usually 16-inch thick and provide a very quiet interior space.
When used with other sustainable techniques such as double- or triple-glazed south facing windows, locally sourced beetle-kill lumber and recycled steel roofing, a very comfortable environment can be created to provide low maintenance, low operating costs, rainwater collection, and use of solar energy stored in the adobe for heating.
The adobe home is one of the most sustainable habitats for any space traveler.
