You know, if you take away the lack of air and water, the weaker Sun, the lower gravity, and the toxic soil, Mars isn’t all that bad of a place to live. And there are certainly worse places to live, like, I don’t know, Ohio (I’m allowed to say that because I grew up there). But there’s been a big push in the past two decades to not just go to Mars and visit, like we did with the Moon fifty years ago, but to stay there. Put down roots. Establish ourselves. Build a colony or a settlement.
We’ve got the Mars Foundation, we’ve got Occupy Mars, we’ve got Mars One. All of them propose grand plans to build a human settlement, a city, on the Red Planet within the next generation.
I’m going to give it to you straight, because if you’re watching this show then I bet you’re the kind of person that appreciates a no-nonsense approach.
We’re not going to Mars anytime soon.
I know there are some…announcements…floating around out there, and at the time of this recording WHO KNOWS what the current administration will propose, that say that we should go to Mars in 2026 or 2029. I can tell you with utmost confidence that the people throwing out those dates aren’t doing it because they have a well thought-out plan of technological improvement to make those reasonable targets.
They’re doing it because those are the next open launch windows. That’s it. Let’s go to Mars in 2026…because that’s the next time we can go to Mars. It’s like saying “hey everyone I have a plan: we should all go to Barbados at 7:19 tomorrow morning”…because that’s when the next flight is leaving, not because you’ve actually developed a plan to go to Barbados. Or even have the money. Or a swimsuit.
But while we can be pessimistic about the short term, we can still be optimistic about the far future. There is no law of physics that makes a Martian settlement impossible. Sure, it will be perhaps the toughest engineering challenge EVER, but it’s not IMPOSSIBLE – and that’s a big difference.
So let’s dive into what a Martian city might actually look like and how we might be able to build one. But first, we need to talk about how a city on Mars will be completely unlike anything we have on Earth.
Because it’s Mars.
Let’s start with the raw numbers. The average temperature on Mars is minus 63 degrees Celsius, or -80 Fahrenheit. While it can get warmer than that, up to something approximating room temperature in the low-lying valleys during the summer months, it can also get much colder than that, down to -153 Celsius or -225 Fahrenheit.
Remember, Mars is a planet cold enough to freeze not just water, but also carbon dioxide.
So number one, any human settlement is going to have to grapple with extreme, bitter, year-round cold. Even the most remote and extreme places on Earth, like the South Pole, don’t reach temperatures that low.
And the South Pole has the advantage of you know, having air to breathe, which Mars lacks. The air pressure on Mars is less than 1% of the air pressure on Earth at sea level. And what air is DOES have is mostly carbon dioxide, which is great news…if you’re a plant.
Now it’s not that complicated to build a pressurized vessel to maintain a regular, breathable atmosphere against what is essentially a vacuum. The International Space Station does it all the time, and it’s pretty big…and it’s also designed to hold no more than a few people at any one time. And it’s right there in Earth orbit, making resupply and – if needed – evacuation relatively straightforward, at least as straightforward as anything goes in space.
But Mars isn’t close. The average distance to Mars is 140 million miles, or 225 million kilometers. With chemical rockets, a journey there takes MONTHS. Just think about it: usual crew rotations for the space station are around that same length of time. And the Apollo missions to the Moon were much, much shorter. So a typical astronaut stay at hotel ISS is roughly equal to JUST THE JOURNEY TO MARS, not including actually, you know, being there and coming back home.
And even then, we have to wait for a launch window to open up when the Earth and Mars are on the same side of the solar system, which happens roughly every two years.
Sorry Mark Watney, but rescue is not going to be an option. Nor is resupply. If something goes wrong or the settlers runs out of some critical component or ingredient…that’s it. They’re going to have to figure it out on their own.
Adding to their daily headaches will be a constant exposure to cosmic rays. This is deadly radiation coming in from deep space, from exploding stars and black holes and whatnot. On Earth our atmosphere does a wonderful job of absorbing most cosmic rays, but even then they’re able to slip through to the surface. You are struck by a cosmic ray about once every second, and these cosmic rays contribute to somewhere between 1-3% of all incidents of cancer.
Mars has no atmosphere. Which means the Martian surface gets a lot of radiation. And just simple metal shielding isn’t going to cut it. That’s because a cosmic ray can just strike the metal and create a shower of subatomic particles within the shelter. You need a lot of stuff – rock, water, gas, whatever – between you and the dangerous sky.
Speaking of rocks, yeah they’re toxic. And not like social media personality toxic, I mean actually toxic. Poisonous. Dangerous to touch, breathe, ingest, or otherwise be around. The soil is full of perchlorates, which is sometimes used as an ingredient in rocket fuel. Any food that’s grown on Mars will have to use treated soil, which will use who knows how much water.
Oh, that’s right, water. Yes, there’s water on Mars, but it’s almost entirely frozen. There might be some liquid pockets buried deep under the polar ice caps, which isn’t anything remotely resembling accessible, so we’ll just have to leave those be. The rest of the frozen water is buried underground, which means…mining. A lot of digging up dirt, heating it, sorting it, and separating the water.
Mining itself is going to be a huge problem for any long-term habitation. On the Earth we’re used to just finding ore veins and taking a whack at it. I mean I suppose the actual process of mining is more complicated than that but I’ve played a lot of Minecraft so I feel like I understand the basic gist. On Mars, this isn’t quite so easy. Without plate tectonics to mix up the crust, we have no idea if there are rich concentrations of metals, which means that anything heavy will have to be shipped in from Earth.
And we need to talk about the dust. Martian sand. It’s course and rough and irritating and it gets everywhere. No, wait, actually it’s opposite. It’s been blowing around Mars for billions of years, and that constant motion has ground the dust grains down into almost perfectly smooth, almost microscopic bits. And when dust storms kick off, they can literally encircle the entire globe.
In 2018 just such a global dust storm killed NASA’s Opportunity rover. The storm blocked out the Sun for so long that the rover couldn’t get enough juice from its solar panels, and it went quiet. Any future settlers will likely need to rely at least in part on solar power, which means they will be in a constant fight with the dust starting at day 1.
Like I said, we’re not going to Mars anytime soon, because we haven’t solved…let me check my notes…ah, that’s right, ANY OF THESE PROBLEMS. And we’re not going to solve them in just a few years.
But that doesn’t mean we can’t make progress.