How Would Humans Protect Themselves On Mars?

To survive on Mars, humans would shelter inside pressurized habitats shielded from radiation by thick water ice, piled-up soil (regolith), or underground lava tubes. Going outside means a pressurized spacesuit and a portable oxygen supply, since the thin air is roughly 95% carbon dioxide. Breathable oxygen and even rocket fuel can be produced on-site from local ice and the atmosphere, as NASA's MOXIE experiment proved.

This might sound a bit depressing, but things aren’t going particularly well here on Earth. Despite huge advances in technology and collective intelligence around the world, there are major issues facing this planet that often seem insurmountable. Between climate change, rising political and social tension, and a population that keeps climbing, some people can’t help but look for ways to escape.

For those people who are truly fed up with life on Earth, they are even looking towards the stars, or at least the nearest planet that could support life – Mars. The idea of colonizing and surviving on Mars has been thrown around a lot in recent years and decades, but there are some serious obstacles – such as freezing temperatures, a lack of oxygen, and extreme cosmic radiation. With all that standing in the way, many people are asking… how would human beings possibly protect themselves in the harsh Martian landscape?

Short Answer: Possible solutions include ice-insulated igloos, soil-covered or lava-tube shelters for radiation shielding, robot construction crews and making oxygen on-site.

Setting Up Camp

We have already managed to send rovers and unmanned missions to Mars, so we are confident in our ability to make the trip, but once potential colonists or researchers arrive, there needs to be somewhere they can be protected from the harsh environment of Mars. Remember, the average temperature on Mars is roughly -60 °C (-80 °F), as compared to an average of about 15 °C (59 °F) on Earth, and Martian nights can plunge well below -100 °C (-148 °F).

To make “base camp” on Mars, it is suggested that robots would first be sent to Mars to construct the necessary habitat, as they can function and survive in the unforgiving conditions of the planet. These robots could also be tasked with extracting resources from the Martian surface, decontaminating them, and essentially stockpiling the things future colonists would need. Growing food would be essential for long-term colonization, but the Martian soil is laced with perchlorates, toxic salts found across the planet at concentrations around 0.5%. In humans, perchlorate blocks the thyroid from taking up iodine, and it is harmful to plants too, so the soil would have to be rinsed or chemically treated before anything could be grown in it. Robots could begin that leaching process and set the stage for agricultural efforts, just like many of you saw in The Martian!

With those supplies in place, it would be a relatively easy transition for colonists to arrive and begin to operate a colony or base immediately. The atmospheric issues can be countered by current technology, such as spacesuits, like those currently used by astronauts, which can provide the necessary oxygen. The atmosphere on Mars is less than 1% the density it is on Earth, and roughly 95% of that thin “air” is carbon dioxide, which is unbreathable for humans. Worse still, Mars lost its global magnetic field billions of years ago, and its feeble atmosphere stops almost none of the radiation pouring in from space. That means a steady drizzle of high-energy galactic cosmic rays, punctuated by sudden bursts of solar particles, a dose that settlers couldn’t survive out in the open for long, which brings us to the real crux of the “living on Mars” problem – the shelter.

What Does Home Look Like?

In 2016, an old architectural concept was dusted off and brought back into the light – the igloo. Called the Mars Ice Home, this high-tech igloo will basically be a transparent bubble, with large storage pockets on the edges to hold water and carbon dioxide. The water will turn into ice, due to the freezing temperature of Mars, and that’s where the beauty of this plan lies.

This fancy igloo serves a number of purposes; first of all, the translucent nature of ice means that Martian settlers will be able to get natural light, an impossibility in the other proposed ideas (where astronauts live underground to protect from radiation). More importantly, however, ice (and the liquid water it is made from) is one of the best materials we have for blocking cosmic radiation, which on Mars arrives mainly as fast-moving charged particles, chiefly protons and heavier atomic nuclei, rather than as light.

For those of you who paid attention in chemistry class, you know that H₂O is composed of 2 hydrogen atoms and 1 oxygen atom. That hydrogen is exactly what makes water such a good radiation shield. Because a hydrogen nucleus is a single proton with almost the same mass as the incoming cosmic-ray particles, collisions with it sap their energy efficiently while producing fewer dangerous secondary particles than dense materials like metal would, keeping those inside far safer from the radiation.

This igloo/icy inner tube structure could be extended to other structures, making the “colony” larger, an interconnected network of radiation-free pods and living spaces, where artificial atmosphere could eventually be generated, meaning that colonists could actually live without a spacesuit!

The ice home is not the only plan on the table. Two other approaches lead the field, and both lean on the same idea of putting mass between people and the sky. The simplest is to bulldoze loose Martian soil over a habitat: studies suggest a layer of regolith roughly 1 to 1.6 meters (about 3 to 5 feet) thick would cut a settler’s yearly radiation dose to a tolerable level. The other is to move in for free, using Mars’ natural lava tubes, large hollow tunnels left behind by ancient volcanoes. A few meters of rock overhead shields against cosmic rays, solar flares, micrometeorites, and the wild day-to-night temperature swings all at once, which is why these underground caverns are among the most promising real estate on the planet.

How Close Are We To Living On Mars?

While the prospect of living on another planet is becoming more attractive by the day, there are still quite a few hurdles before we reach the Red Planet. From Barack Obama to Elon Musk, a lot of projections have recently been made about when and how we are going to colonize Mars, but some people remain skeptical.

First of all, a crewed mission is a marathon. With today’s rockets the journey is roughly six to nine months each way, and because Earth and Mars only line up favorably about every 26 months, a crew would have to wait out more than a year on the surface before the return window opened, making the whole expedition close to three years door to door. That means hauling years of supplies and giving people room to live comfortably during long-term space journeys. It means building bigger spacecraft, which in turn means building more powerful rockets. SpaceX, Blue Origin, Lockheed Martin and NASA are some of the leading names in these efforts, and SpaceX is developing its giant, fully reusable Starship vehicle (the kind of rocket that could one day even launch satellites and spacecraft from the Martian surface) with Mars settlement as its stated long-term goal. Timelines keep slipping, though: in early 2026 SpaceX pushed its first uncrewed Starship flights to Mars back by several years to concentrate on the Moon, so a crewed landing is now widely expected no earlier than the 2030s. So far, every craft to reach the surface has been robotic, not human.

We often think about the ISS as being in outer space, but in truth, it orbits in low-Earth orbit, where Earth’s magnetic field (the same field that shapes the Van Allen radiation belts) still deflects much of the incoming cosmic radiation. On a long journey through deep space, far beyond that magnetic umbrella, additional consideration will need to be taken to protect travelers from the much higher levels of radiation pummeling the spacecraft during the trip. Safely landing on the surface of Mars using supersonic retropropulsion is also a tricky prospect, but one that SpaceX and other companies are working on with their reusable rockets and spacecraft.

There has been real progress on living off the land, too. On April 20, 2021, a toaster-sized instrument on NASA’s Perseverance rover called MOXIE (the Mars Oxygen In-Situ Resource Utilization Experiment) became the first device to make breathable oxygen on another planet, splitting it out of the carbon dioxide in the Martian air. By the time it wrapped up in 2023, MOXIE had run 16 times and produced about 122 grams (4.3 ounces) of oxygen in total. The amounts are tiny, but the proof of concept is huge: future crews may be able to manufacture both the air they breathe and the oxidizer for their return-trip rocket fuel right there on Mars, rather than dragging it all from Earth. Perseverance, meanwhile, keeps caching rock samples for an eventual return to Earth, and its companion helicopter, Ingenuity, flew 72 times before retiring in January 2024.

As you can see, there are numerous obstacles that still exist to this dream of a Martian colony, but with a global interest in this newest space race, it’s only a matter of time before we solve these problems and take our next tiny steps into the unknown!