The Low-Tech Way to Colonize Mars

Philip Metzger has been playing with mud. Experimenting, you could say, as he’s a planetary scientist at the University of Central Florida and co-founder of NASA’s Swamp Works lab. In any case, his lab has been stuffing Martian clay into cupcake decorating bags and extruding it into what Metzger himself admits sometimes look like an “animal dropping.”

But one man’s cupcake decorating with mud is another man’s prototyping of 3-D printing on Mars. And 3-D printing could solve the single biggest hurdle to a crewed Mars expedition: the cost of transporting everything humans need to survive on the red planet.

It’s a mass problem. The more mass you have to take, the more expensive it is to escape Earth’s gravity and get to Mars. And some of the heaviest cargo will be material to shelter astronauts from the radiation zipping through Mars’ thin atmosphere. With 3-D printing, you don’t need to bring shelter. You build it out of dirt or ice already on Mars.

NASA is all aboard the 3-D-printing train. Last year, it unveiled winners of its first 3-D-printed Mars habitat design challenge, and the architectural renders of the winning entries were all sleek and futuristic, as renders of unbuilt buildings always are (see above). In reality, the current state of the art for Martian 3-D printing looks more like the clay logs Metzger has been documenting on Twitter.

Martian (sim) clay logs. Top: still damp. Bottom: vacuum dried. I'm surprised the 50% mix crumbled so badly. Need to repeat w/ more samples. pic.twitter.com/H9Sug4TB09

— Dr. Phil Metzger (@DrPhiltill) October 13, 2016

If the technology looks low-tech, it’s deliberate.

“We’re rethinking how to do space technology by taking cues from less developed parts of world,” Metzger says.

The logic goes like this: If a valve breaks in a complex machine on Mars, an astronaut can’t go online to order a replacement with next day delivery. (It’s more like nine months, assuming Mars and Earth are in their most favorable alignment.)

So the idea is to start simple and slowly build up technological capabilities: clay to metal to plastic to electronic equipment. Eventually, Mars will have the refineries and factories to make complicated machines itself. This is “bootstrapping,” and it’s Metzger’s vision for space exploration.

Should you ever find yourself doubting human ingenuity and persistence, spend a few minutes with the mesmerizing YouTube videos of Primitive Technology. In each video, a man—unnamed, silent, dressed only in shorts—goes out into the Australian outback with his bare hands. He might dig up some clay, make a coiled pot and fire it in a small fire. He then goes back to the clay pit with his pot, this time able to carry more clay, and gathers enough material to build a kiln. He gets even more clay, makes tiles and fires them in the kiln. Eventually, weeks later, he has an entire tiled hut, complete with mud walls and an underfloor heating system.

Each individual step is slow and unremarkable, but their cumulation—a tiled hut out of bare hands!—is awesome. This is bootstrapping, on the scale of one man.

American colonists, argues a 2011 NASA paper on space exploration, also bootstrapped their way through North America. They arrived with a few tools  and scrabbled out a living in the harsh, unforgiving environment of New England. Simple pools begat more sophisticated tools, and over time, North America built up the shipyards and ports that turned it into a trading power.

“Like colonial America, the growth process is a very slow and methodical,” the paper reads, “It will take years to evolve but in the end a very permanent infrastructure will emerge that will change how humans explore and develop space.”

In space—an environment where “harsh” is an understatement—bootstrapping might start with more sophisticated technology: robots. Robots are easier to send than humans, with their finicky needs for oxygen, food and water. But these robots, like the man in the Australian outback, will likely start with extremely simple tasks like digging up dirt. Dirt that could be turned into roads, blast walls, or shelters with enough 3-D-printing ingenuity.

Metzger became intrigued by the idea when he realized Mars may have the same clay minerals as Earth. (The same is true for asteroids, which could be used as depots for interplanetary travel.) No one and nothing has ever returned to Earth with Martian dirt, of course, but probes and rovers of the decades have picked up chemical signatures hinting at the clay minerals.

So to test whether 3-D printing clay could ever even work on Mars, he had to figure out how to simulate Martian clay on Earth. It helps that laws of chemistry and physics are the same.

“You have chemical interaction on the surface of Mars that produce some fairly predictable products, like clays and sulfides,” says Daniel Britt, a collaborator and geologist at the University of Central Florida. “And you know there’s environments on Earth that do the same thing.” The team called around to state geologists’ offices to find the mines with the different kinds of clay minerals to make Mars “simulant.”