What If We Built a City on Mars?

The next step in space exploration isn’t generations away. It’s happening right now. And our destination? That mysterious, desolate world next door, Mars. Imagine starting life over on that tiny red dot over 265 million km (16.5 million mi) away. What would happen if we built a city on Mars?

Would you have to live underground? How many people would you live with? And, what would the Martian economy look like?

Since 1975, the only thing from Earth making claims on Mars are robots and satellites. But now, Elon Musk and his company SpaceX are looking to change that story. Their goal? To create a city with a government, trade, and culture – on Mars.

This plan involves 1,000 spaceships and even more brave new recruits. By surviving in lower gravity, with fewer people, and only limited supplies, living on Mars might change how we could adapt to dwindling resources on Earth. But with so much depending on the early stages of planning and supply runs, could life on Mars become sustainable?

Every great city starts small, whether you’re talking about the fishing town of Hong Kong or a hut village named Rome. So if you want this Martian colony to grow into a thriving city, you’re going to need more than a handful of people.

According to the Bordeaux Institut National Polytechnique, you would need at least 110 settlers to start this adventure. The SpaceX plan starts with two spaceships carrying 100 people each. With this handful of explorers, your city would have just enough people to build more habitats and research stations without putting your resources in danger. If you run out of food at this stage, that’s the end of this experiment.

The biggest challenge this city faces is becoming sustainable without relying on regular shipments from Earth, which will only come every few years. See, with the egg-shaped orbit of Mars, it takes 687 Earth Days to make one Martian year. Supply runs would only launch when Earth and Mars align, which happens every two years to cut down on travel time between our worlds.

And after this nearly eight-month-long trip, there’s still a chance of losing all those supplies when the rocket lands. Since the gravity on Mars is only three-eighths of the pull on Earth, landing safely on the surface of Mars would be dangerous.

And that doesn’t take into account the dangerous amount of dust flying in the air. After all, the dust on the moon was bad enough, and it got into crew members’ eyes and damaged systems on their spacecraft.

But kicking up the dust on Mars might be even more deadly since each grain is highly oxidized and electrically charged. But hey, you made it to Mars safely. Cool. Now, what are you going to eat?

The chlorinated soils on Mars are toxic, and if you ingested them with your food, you might damage your thyroid gland. So that means farming is out. Outdoor farming, at least.
Well, before you worry about eating, you’ll need to set up protection from the harsh conditions on Mars. With an atmosphere made of 95% carbon dioxide, the air on Mars is toxic. And don’t forget the intense radiation on the surface. With more exposure to radiation and no breathable air, you won’t survive without a controlled environment.

Thankfully, with the help of those rocks under your feet, you have all the protection you need. Just 5 m (16 ft) of the surface materials on Mars, called regolith, provides the same amount of shielding from radiation as Earth’s atmosphere.

This material would be processed into cement to create layered walls using robots and 3D printers. This material would be a protective shell. And underneath that shell? Domed science facilities, living spaces, and all your home comforts. Connected by tubes, these domes would provide you shelter from the raging dust storms outside, which might last for months.

Costing as little as $4,000 per home, some companies on Earth have constructed 3D-printed houses around 75 m2 (800 ft2), and all built within a day. Even with this technology, Elon Musk claims it could take up to 10 years to establish a colony. But it’s during this time that your quaint Martian village would grow into the first human city beyond Earth.

Since this world isn’t being drilled or fracked, the power grid on Mars can be made sustainable right from the start. We would set up solar arrays for electricity and use natural gases like methane for engines. Our footprint on Mars could start low and stay that way, no matter how many people live there.

And now you better figure out a way to feed all these people. The low gravity on Mars might decrease your muscle mass. To keep your body healthy, you’ll need to provide more protein. You’ll have to serve the equivalent of 110 cooked chicken breasts and 660 carrots every day.

If one of these domes contained an indoor farm, you could raise the chickens you need to feed your city. And you would have the most nutrient-rich manure available. If you used this manure in the greenhouses, you’d have a way to fertilize your crops year-round. But how could you irrigate those crops? How would you get water?

Scientists still debate whether liquid water exists below the ice caps on Mars. But if it does exist, that freshwater source could be filtered for the colonists to use for irrigation. With less gravity pulling water down into the ground, you would need less water to keep your plants alive since it would stay closer to the surface.

With supplies transported every two years, having spring water available on Mars would change how the city would operate. It would create a government infrastructure to distribute and oversee the water supply and employ scientists to manage the filtration needs.

Now the city has an infrastructure in place and jobs to fill. So how would you value your time in terms of cash? How could you pay for products or services? Cash weighs too much to travel with in outer space. And credit cards would require wifi services communicating back to Earth. With a 14 min gap in communication between Mars and Earth, you’re going to need something locally based.

Well, you might have to use a cryptocurrency known as MarsCoin. But, you would’ve needed to have bought in it with your Earth money before you boarded the spaceship. While MarsCoin would only be available to Martians, this money would help build the government, increase trade, and create a standard of living. With society on Mars still new, maybe you could trade your services or learn to barter goods instead of relying on this cash system.

If we do things right, life on Mars might be the model for future civilizations, free from the constraints of the culture built on Earth. Or it could be like every sci-fi movie ever made. But maybe Mars is too tame for your tastes. If you’re willing to move to Mars, you want to push the boundaries of what’s possible.