Living on another planet is going to be really hard. No readily available food, water, or breathing air. Extreme cold and extreme hot. No atmosphere or magnetic field to protect from the sun’s radiation (or meteorites). The buildings that colonizers live in will be incredibly important–they’ll need to keep inhabitants safe from all of the above.
That’s why NASA is asking private companies to come up with ways to build these homes through its 3D-Printed Habitat Challenge, a competition to design habitats and laboratories for deep space exploration. The objective isn’t just deep space design, though–NASA also wants to advance construction technology that could help create sustainable housing solutions on our home planet.
The challenge has been going on since 2015, as NASA puts entrants through a series of hurdles that narrowed the race down to a few ideas. This week, the agency announced the winner of its latest phase: the New York-based startup AI SpaceFactory, which proved its tech in a real-life simulation last week.
Starting on May 1, the startup spent four days competing against the other finalist, a team from Penn State University. In total, they spent 30 hours 3D printing their habitat design at Caterpillar’s Edwards Demonstration & Learning Center in Edwards, IL.
Both teams’ technologies used robotic arms that could operate autonomously in another planet, with minimal human intervention, and used raw materials that could be found on Mars and the moon mixed with recycled materials from earth. Their methods for making these building materials differed, though. Penn State used cement made from river sand similar to Martian soil. AI SpaceFactory’s 3D printer laid down a composite material that mixes basaltic fibers that could potentially be harvested on Mars and bioplastic made from starch that would be shipped from earth.
The architectural design between the teams was different, too. Penn State’s habitat resembled Italian trullos—cylindrical structures with conic roofs–while AI SpaceFactory built a 15-by-8-foot egg-shaped structure. While the built mock-ups are only one-third of the full size, they had to endure rigorous testing, like direct hits from heavy balls to simulate accidents and sustaining 50,000 pounds of force to test overall durability against extreme weather.
AI SpaceFactory’s approach resulted in significantly better results during the testing process. For example, according to IEEE Spectrum, when a 96-ton Caterpillar’s excavator pressed the structures from the top, the egg-shaped composite structure designed by AI SpaceFactory hardly budged. Only a tiny bit of the material broke, leaving the building intact. The Penn State cement habitat, however, crumbled after showing enough resistance to lift the front of the Caterpillar’s threads from the ground. In another test, a 29-pound ball was fired onto the structures, causing serious damage on Penn States’s design but none for AI SpaceFactory.
This isn’t the end of the competition, nor the end of the road for a viable 3D-printing Mars habitat. With the data gathered during the test, and armed with their $500,000 and $200,000 awards, the two teams will now refine their technologies for a new phase of the $3.5-million competition that is yet to be defined.
In the meantime, the New York company will recycle the material and use it to build a new design called “Tera,” which they actually want to turn into an Airbnb–one that you can actually book without being Elon Musk.
Beyond that, the project awaits further development until the tech is mature enough to be used in a future mission.
I asked AI SpaceFactory’s CEO and chief architect David Malott how he imagines his system getting to Mars and building habitats there. He envisions two rovers, sent in advance of astronauts in a rocket: one to gather and process the materials for the 3D printing, the other to actually print the habitat.
“The robots will autonomously construct the habitat and ideally pressurize and fill it with an earth-like atmosphere, before the arrival of the first [humans],” he says.
Some experts believe that we should avoid building anything on Mars and instead work with existing geological features, like lava tubes and caves, to turn them into human habitats–because this approach would be more cost-effective and provide natural radiation shelter. Malott disagrees. “Humans much prefer to live above the ground with windows [rather] than burrowed into the ground or in caves,” he says. “The biopolymer-basalt derived material we have developed should provide effective cosmic radiation shielding due to its low atomic mass.” He also believes that they might enhance shielding by depositing ice between two layers of 3D-printed material (“like a Martian ice cream sandwich”) but admits that they still have to validate these ideas with actual testing.
Malott believes that inflatable habitats installed in caves could be a temporary habitation measure, but he thinks it’s not the best solution. The key to any future Martian or moon habitat is permanence, and inflatable habitats in caves won’t fulfill that objective. You can build a 3D-printed habitat nearly anywhere–close to ice water, metals, or soil that can facilitate life on a permanent colony on Mars. After all, it’s a process that humans have been perfecting since the beginning of civilization: finding ideal locations with favorable conditions to raise their villages, towns, and cities.