As the greatest challenge of the 21st century and Elon Musk’s legacy, colonizing Mars in its current state seems almost impossible. But in any case, what would it look like if we tried?

Let’s explore a couple of challenges.

First, let’s consider some of the major elements a human civilization requires:

1. It has to be completely self-sustaining;
2. and it has to be liveable for long periods of time.

But these are especially difficult to accomplish for human beings because of all of our needs.

For a basic understanding of the difficulty of these challenges, let’s compare planets.

Here are some factors that affect our potential to live on Mars.

Similarities

• The length of a day (1d 37min) ⁶
• Terrestrial planet

Differences

• Atmospheric makeup (mostly carbon dioxide, some water vapor) ⁶
• The average temperature is lower than that of the Earth (-81°F or -63°C) ⁶
• The length of a year is twice as long (687 days) ⁶
• Gravity is 0.375 that of the Earth (3.711 m/s²) ⁶
• Water deposits under the planet’s surface ⁵
• Mars has large dust storms  ⁵
• High radiation on Mars (30 µSv/h) ⁴
• Low solar energy potential (over 50 million km further from the sun) ^{5, 6}
• Low atmospheric density (also low pressure) ⁵
• Soil toxicity (contains perchlorates) ¹

Based solely on this list, Earth and Mars are clearly very different planets, which means we have got a lot of work to do.

The transformation

Assuming terraforming is off the table, we have to find solutions to these problems from Earth.

So… let’s begin.

Figuring out how to breathe

Based on its different atmospheric makeup, living on Mars for human beings is impossible due to the low levels of oxygen available. ⁶

Through a process called electrolysis ⁴, we can use water and energy to maintain healthy oxygen levels by decomposing the water molecule into its two separate parts through the electrolysis reaction. This will result in separate hydrogen and oxygen atoms which we can make use of.

Chemical formula: 2H₂O → 2H₂ + O₂ ⁴

The resulting oxygen can be used to sustain the crew (breathe) and given the leftover hydrogen atoms, we could potentially combine them with carbon dioxide — which is abundant in Mars’ atmosphere — to make water and methane. ⁴

Chemical formula: 4H₂ + CO₂ → 2H₂O + CH₄ ⁴

Currently, hydrogen application research has also been developing within the energy field which has the potential to have an even greater impact on our colony’s well being on Mars.

After the methane reaction, the resulting water can then be recycled in the electrolysis process and methane can be used as a fuel source to make heat and light. ⁸ Another great use of methane is as a potent greenhouse gas in order to help slowly thicken the atmosphere.

Temperature regulation

Based on Earth’s average temperature of 57°F or 14°C, ⁸ the temperature on Mars becomes another hurdle to overcome.

To make sure our fragile human species is able to live comfortably on this new planet, we have to find a source of energy to keep our colonies at a comfortable temperature or buff up the atmosphere to trap in more heat.

The most obvious solution is harnessing solar energy off the sun because of Mars’ thin atmosphere, but the problem with the solar potential on Mars is that it is a fraction of the potential available on Earth. ⁵ Due to its further distance ⁶ and the reoccurring dust storms on the planet, ⁵ solar energy is not a suitable nor reliable energy source.

Due to its low core temperature and thin atmosphere, many other sustainable/green energy sources are out of the question which makes nuclear our only obvious choice. ⁵ The entire power plant would have to be brought to Mars from the Earth and all nuclear materials would also need to be imported increasing Mars’ dependence on Earth.

Due to the fact that Mars takes twice as long to make one revolution around the sun (687 days), ⁶ there is a very short window for the Earth to make contact with the Mars colony. When able to, the Earth would have to send tonnes of nuclear resources all at the same time resulting in the dependence on Earth which adds more risk to this mission.

The reason why we must find energy sources to keep ourselves warm rather than finding a more long lasting solution is because the lasting solution takes too long. Thickening the atmosphere through the greenhouse effect would theoretically take too long and we are looking for a more immediate solution for our inhabitants on Mars.

Finding water

Years ago, scientists began theorizing Mars has huge water reserves underneath the surface of the planet ⁵ which gives it the potential to sustain human life. Finding an ideal spot for our first inhabitants on Mars will take a lot of planning as it has the potential to make or break the colony’s success.

Scientists found these reserves frozen under the poles of the planet which will give humans both oxygen (electrolysis) and water to allow them to live.

The soil on Mars can also be used as a source of water. After finding an ideal location with a high concentration of water in the soil, the colony can extract water by simply heating it up and evaporating the water. ⁹

As a sustainable addition, distillation methods along with filtration systems can be used to recycle water. This method of reusing water is currently being used by astronauts on the international space station which can also be accommodated for our Mars colony. ⁷

Protection from radiation

Another huge difference we have to consider is the way the Earth and Mars protect themselves from radiation.

Mars has one percent the atmosphere of Earth and its electric field is almost nonexistent in comparison. As a result, half of all radiation coming from space reaches the surface of Mars. ⁵

In an attempt to shield our colony from this space radiation — which is lethal to humans — each settlement on Mars could utilize several meters of soil as a cover on top of each habitat ³ along with a layer of frozen CO₂ ⁵ to provide reliable shielding against even galactic cosmic rays. Five meters of soil will provide a similar degree of protection as the Earth’s atmosphere to keep the settlers safe. ³

Another side effect of a low atmospheric density provided by Mars is that atmospheric pressure is also low. To make sure that pressure is maintained, settlements must be pressurized with oxygen and nitrogen to simulate Earth’s atmosphere and allow for humans to safely live there. ⁵

The effect of low gravity

There are also many major low gravity side effects that astronauts encounter as their bodies adapt to the new environment.

The first most prominent physiological effect is space sickness. This occurs to about 45 percent of people as they adapt to their new weight in space. ¹⁰

On the way to Mars, the crew will experience all types of health problems such as loss of muscle mass, redistribution of fluids, compromised hand-eye and head-eye coordination, compromised balance, loss of spatial awareness, cardiovascular deconditioning, and other physical issues. ² Some of these issues and others act up if the crew does not consume the needed nutrients and exercise enough.

These types of gravity inducing problems will occur on the way to Mars without proper exercise and diets. In this case, the crew would be severely inadequate to perform tasks. Therefore, the crew would have to undergo constant evaluations to maintain their physical abilities in space as well as on Mars. This is because the gravity on Mars is still less than that of Earth which would continue to trigger some physical issues on the human body.

Growing food on the toxic land

The final problem we need to solve is finding ways to grow food on the martian soil. Due to the alternate makeup of the soil on Mars, it is an unsuitable environment for Earthly food growth. ¹

Food production would have to occur in simulated indoor areas with artificial lighting. Carbon dioxide for plant growth would be available straight from Mars’ atmosphere, water would be recycled and given to plants, and nutrients would be recycled through human waste. ⁵

But, why Mars?

Based on current estimates, the people living on Earth are not very hopeful of its future. Based on the fact that at some point we must find a new place to live, Mars seems to be the next best option. With SpaceX’s mission of making life multi-planetary, they have already begun paving the path to a brighter future.

References

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2. Dunbar, B. (2020, February 6). The human body in space [Text]. NASA. http://www.nasa.gov/hrp/bodyinspace

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4. Kruszelnicki, K. S. (2015, June 9). How do astronauts breathe in space? ABC Science; 2020 Karl S. Kruszelnicki Pty Ltd. https://www.abc.net.au/science/articles/2015/06/09/4249936.htm

5. Kurtzgesagt. (2019, February 3). Building a Marsbase is a Horrible Idea: Let’s do it! [Video]. YouTube. https://www.youtube.com/watch?v=uqKGREZs6-w

6. Mars facts. (n.d.). NASA Science Mars Exploration Program. Retrieved August 12, 2020, from https://mars.nasa.gov/all-about-mars/facts

7. Mathewson, S. (2016, November 16). How recycled astronaut pee boosts chances for future deep-space travel. Space.Com; Future US, Inc. https://www.space.com/34688-recycled-astronaut-pee-boosts-deep-space-travel.html

8. Methane. (2018, January 30). Wisconsin Department of Health Services. https://www.dhs.wisconsin.gov/chemical/methane.htm

9. Will the astronauts have enough water, food and oxygen? (n.d.). Mars One. Retrieved August 12, 2020, from https://www.mars-one.com/faq/health-and-ethics/will-the-astronauts-have-enough-water-food-and-oxygen

10. Williams, M. (2017, May 1). Pardon my vomit—Zero-G etiquette in the age of space tourism. Phys.Org; Phys.org. https://phys.org/news/2017-05-pardon-vomitzero-g-etiquette-age-space.html