Let’s say you’ve picked the perfect spot for building a settlement on Mars. But this opens up some pretty nasty questions. Building…what? And building….with what? There are no trees to chop down to construct temporary structures. There are no campfires you can build to keep warm while you start. There’s no…I don’t know…WILD GAME to hunt to feed yourself.
Mars is dead.
Martian settlements will forever be limited by what supplies can be sent from Earth: it’s a long, slow, dangerous trip, with launch windows open only every two years, with each launch costing hundreds of millions of dollars at MINIMUM. This means that any Martian settlement will have to rely almost entirely on natural resources, something called in-situ resource utilization. Using what’s already there to get the job done.
So we have to be very clever with what we build, where we build, and how we build.
We can probably assume that the first Martian settlers will have some temporary structures available to them. After all, settlements won’t begin in earnest until we’ve already sent many missions to the surface, and we can build off of what those missions leave behind: shelters, rovers, solar panels, uh, wrenches, you know, stuff.
The first settlers won’t be completely empty-handed. Plus they’ll have their own decent modules and materials sent in advance. But to really build out a settlement you need to build, which means you need a lot of raw materials. So much raw materials that we just can’t ship it from Earth. It’s too much mass. We need to reserve that precious cargo space for equipment that we can’t develop directly on the surface: specialized medicine, advanced robotics, and unique cheeses.
In 2006 a researcher named Bruce Mackenzie with the Mars Foundation developed the Homestead plan, which reasonably approximates the steps a future Mars settlement would have to perform to become self-sustaining, and what they can safely assume and not assume given another few decades of technological development.
The plan calls for the use of a hillside base. This way the people can safely take cover from radiation, but also easily access everything that needs to be exposed to the surface. The plan minimizes drilling and excavating, which is probably going to be a major pain in the neck for quite some time.
But the plan does call for SOME heavy gear to make it to Mars. Namely three “small” nuclear reactors to provide a baseline source of power (I know I just said that we shouldn’t rely on nuclear power but here we are anyway), and some miscellaneous mining, refining, and manufacturing equipment. The goal here is to take large amounts of the stuff that’s readily available on Mars (water, carbon dioxide, and Martian dirt) and mix it with small amounts of stuff that have to be imported from the Earth (like precious metals).
This means that there’s a lot of chemistry going on, to make oxygen, nitrogen, fuel, and so on.
And then there’s bricks. Many of the habitat structures will simply dig themselves into the hillside itself, using all those tons of rocks to not just protect against radiation, but to maintain the pressure and heat within the modules. But you still have to build a lot of stuff outside the hill, like greenhouses, storage tanks, and, you know, the outside parts of the hillside.
Mars has a lot of dirt – it does have that going for it. And you can use old-fashioned kilns to turn that dirt, reinforced with something like fiberglass, into bricks.
You also need a lot of glass – or something transparent. This is so that your settlers can look outside every once in a while. But it will also be essential for greenhouses. There’s no way that we can ship enough food from Earth to sustain a group of settlers for years upon years. They’ll have to grow some food locally. While they will use artificial greenhouses, that will take precious energy to run, potentially straining the power output of either nuclear plants or solar arrays. So that will have to be supplemented with sunlight greenhouses…which need a lot of glass.
Lynn Rothschild, a senior research scientist at NASA Ames, has a better idea. Grow it. Not the food (although you want to grow that too), but the buildings! She leads a team investigating the use of mycotecture. The idea is that we pack up a frame and a dormant strain of fungus. The fungus is genetically adapted to thrive in the harsh Martian environment. Then we set up the frame and pour some water on the fungus, letting it grow around the frame, creating a sealable, pressurize interior. The team has already been able to grow small structures this way, and developed a technique to make fungus-based bricks out of simply ingredients.
Fungus-based Martian habitats? Practical AND delicious!