Colonising Mars is no easy task. Elon Musk, the founder of SpaceX, has estimated that the current cost of sending someone to Mars is “around $10bn per person”. And there are all sorts of other logistical hurdles involved. But, if we want to expand into the Solar System, we’ll need to find out how to live on other planets. And compared to the other celestial bodies, the Red Planet is the best candidate.
If climate catastrophe strikes, Earth could be well on its way to becoming inhospitable to life.
As abhorrent as the situation is – and while all possible efforts should be taken to avoid further damage – a backup location for humanity may be necessary. And even if Mars doesn’t become a backup home, we may still need to travel there for additional resources, such as precious metals.
Colonising Mars will be a paradigm-shifting moment in the trajectory of the human species. It will be an immense scientific, technological, and psychological feat like no other – an expression of our exploratory courage, hypercharged and craving greatness. The astronauts set for that first and defining migration to Mars will be challenged and personally altered in a number of ways, which I have covered in a previous article. In this piece, I want to hone in on the challenges of colonising Mars, after the long first leg of the journey has been completed. Here are some of the key areas that need to be successfully implemented in order to make possible a sustained presence on Mars.
Surviving on Mars
If Mars is the natural destination for a human colony, how are we meant to survive on a planet that is hostile to human life? You have the extreme cold, an unbreathable atmosphere and intense radiation. While all of this may be true, the ingenuity of humanity may allow us to overcome these difficulties.
In order to deal with the lack of air pressure and cold, we will need pressurised and heated habitats (Bigelow Aerospace’s inflatable habitats are a contender). We’ll also require spacesuits whenever we go outside.
Luckily, Mars does provide some raw materials. The regolith (the material that covers the surface of a planet) could be used to make concrete. And to protect us from the radiation, there are cave systems that could be converted into underground habitats.
For a long-term stay, we’ll have to find some way to extract water from underground supplies, and use that to generate breathable air and rocket fuel. We’ll also have to grow our own food, as it won’t be feasible to ship it all in on a regular basis. Although the Martian soil is toxic, it can be used to grow plants once it is supplemented and the harsher chemicals are removed. We may also have to experiment with genetic engineering, to ensure that our offspring, as well as plants and animals, can adapt to the low gravity, higher radiation and lower air pressure. Terraforming Mars is also a possibility, whereby the surface and climate of Mars is changed to make areas of the planet hospitable to humans. However, this process could take thousands or even millions of years.
There are also challenges involved in the journey to Mars. It is not yet clear if deep-space radiation will degrade the food that future Mars explorers take with them.
Law and Order on Mars
Just because Mars hasn’t been colonised yet, this doesn’t mean some rules haven’t been put in place. The Outer Space Treaty outlines what can and cannot be done in relation to the Red Planet.
First of all, Mars belongs to everybody. The treaty underscores that no-one can own a celestial body. And although Musk wants to terraform Mars by nuking it (well, the sky above the planet), this isn’t allowed – colonists can’t deploy weapons of mass destruction.
Frans von der Dunk, who studies space law, says private companies can go to Mars, build permanent habitats, and start a new society there – as long as they follow the rules of the Outer Space Treaty. For example, the company’s activities shouldn’t interfere with the activities of others in space. Another rule is to avoid contaminating celestial bodies that we explore. This includes keeping the Solar System free from trash, and the planet free from our microbes.
Also, because SpaceX is an American colony, and Musk’s colonists would be travelling on an American ship, they would have to abide by American laws. It’s a lot like maritime laws, where no-one owns international waters, but each ship follows the rules of the country whose flag it flies under. Although there are already some rules in place, we still don’t know what kind of government will be formed on Mars. But that’s the least of our worries right now. Our top priority is figuring out how to safely get to Mars, and then being able to survive in a viable habitat.
Living Sustainably on Mars
SpaceX has argued that reusability is the key to making human life interplanetary. Having rockets that are fully and rapidly reusable will not only save costs in terms of space exploration, but it will make the endeavour all the more sustainable.
On 21 December 2015, SpaceX achieved the biggest cost reduction in space flight history. They sent a rocket to space and then returned it to Earth, completely intact. While this is isn’t as impressive as it going all the way to Mars and returning intact, ready for reuse, this achievement has massive implications. Musk believes this will make a big difference in helping to set up human colonies on Mars.
Normally on its return to Earth, a rocket (or most of it at least) will land in the ocean, never to be seen again. Imagine if the aircraft industry did this with every flight. Flying to another country would soon become astronomically expensive (around £1.2m per economy class seat). But not only that: flying would become even less sustainable than it currently is.
NASA has welcomed Musk’s plans to colonise Mars. In a statement, it said:” We are very pleased that the global community is working to meet the challenges of a sustainable human presence on Mars.” There are, of course, many challenges in humans living on Mars sustainably. After all, we don’t want to repeat the mistakes made with our current home.
One issue with colonising Mars is being able to harvest water in sufficient amounts for long-term survival. Harvesting water will require massive amounts of energy, which many doubt is sustainable.
However, we also continue to learn that the Red Planet is rich with resources. It simply won’t be cost-effective to launch resources such as water and materials to Mars. Indeed, if Mars is to become a long-term or permanent settlement, then we will need to harness technology in order to sustainably use the Red Planet’s existing resources.
In 2016, NASA released a paper titled Frontier In-Situ Resource Utilization for Enabling Sustained Presence on Mars, which argues we’re close to developing technology that would be needed to extract resources with robotic systems. From the paper:
In recent years, measurements by rovers and satellites at Mars have indicated massive amounts of water in the form of ice beneath and within the regolith. At times, during the Martian year, liquid water is observed on the surface of Mars. If the planet were flat and the ice melted, there would be an ocean many meters deep on the entire planet. These huge deposits of water can be extracted in several ways and combined with the large amounts of carbon residing in the 95% CO2 atmosphere to produce life support fluids, fuels, oxidizers, and plastics for equipment, including rovers and spare parts.
Extracting sufficient amounts of water and carbon is key since both can produce materials and fuels that are essential for survival. Minerals are also in abundance, including iron, titanium, nickel, aluminium, sulphur, chlorine and calcium. The most common material found on Mars has been silicon dioxide, the basic constituent of glass, which can be easily produced using sand-melting techniques.
Food will have to be produced in a “protected atmosphere using sunlight”, or perhaps an artificial light source. Possible food sources that could be grown on the Red Planet include “mushrooms, insects, cyanobacteria (e.g. spirulina) and duckweed, along many others.” There is also the possibility of developing a “rice paddy aquaculture”.
At the same time, long-term survival depends on extracting resources in a sustainable way. But if we can live sustainably on Mars, this could have huge implications for Earth, as University of Sheffield student Gillian Finnerty has explained. Finnerty says that “Overpopulation is the biggest problem we have and we will eventually run out of food.” She continues:
If we go to Mars and live in a sustainable manner then it will prove to the people on Earth you can live well without being greedy. It will hopefully inspire people to not take Earth for granted.
So instead of Mars just becoming a backup home – a means of preserving the human race when our current home ‘expires’ – it might become a platform in which humanity can prove how to live sustainably on Earth.
Homes on Mars
A biodome is a form of controlled, self-sufficient ecosystem. A famous example is the Eden Project in Cornwall, UK. And one family in Norway has managed to build and live in one. Here’s why building biodomes on Mars is a highly attractive concept.
A biodome is very similar to the conventional greenhouse since both environments are controlled and allow all different types of plants to be cultivated. However, it differs in some important ways. Firstly, a greenhouse may or may not be isolated from the outside world, which means there could be an on-going exchange of elements such as fertiliser, water and oxygen with the outside world.
A biodome, on the other hand, is completely sealed off from the outside world. Everything is self-supported, with the life cycle processes continuing on their own. A biodome can also conserve energy and water, making it very sustainable, because of its regenerative nature.
We need a way to sustainably maintain life on the Red Planet, and biodomes will allow a Martian colony to do exactly that. We can also live sustainably on Mars by terraforming the planet. But this involves many immense challenges, whereas we already know how to build biodomes on Earth. While there are still definitely challenges involved in building and maintaining biodomes on Mars, the obstacles are not as daunting as those involved in changing the atmosphere of a planet.
There have been a number of proposals for how biodomes on Mars should be designed. Take one example from Tech Brief’s Create the Future Design Contest 2013. The proposal suggests that buildings and houses can be situated inside the biodome so that humans can live in it as well. Plants will supply oxygen. And as for water, if the biodome is built on or near a large ice lake, the ice drilled can be filtered, turned into water, and then put into an artificial ‘water cycle’. Wind turbines could supply the energy.
Also, when creating life-sustaining systems on Mars, there’s no reason not to mine both the atmosphere and regolith to help sustain the dome. Solar panels can be placed outside the dome for extra electricity since wind turbines only work during storms. Arguably, there is little reason to have a completely closed system on a planet full of exploitable resources. So it may not be biodomes that we build on Mars after all, but greenhouses.
The most important thing is that the population within the dome is sustained in an environment similar to Earth’s. While biodomes may be more sustainable than greenhouses, this doesn’t mean that exploiting Mars for its natural resources in order to maintain greenhouses is unsustainable. In the same way, it’s not that using Earth’s natural resources is inherently unsustainable – it’s more to do with how we use those resources.
NASA previously set up a 3D Printed Habitat Challenge, which encouraged teams to design “digital representations of the physical and functional characteristics of a house on Mars.”
But it wasn’t the winning team that has garnered the most attention – it’s the team that came in second. In second place was AI. SpaceFactory, which came up with MARSHA, a cylindrical home printed in 3D by a robotic arm.
Previous designs for human habitats on Mars have been shaped as domes. However, a cylindrical design is much more efficient for a number of reasons. Firstly, the arm of the 3D printer doesn’t have to stretch very far. Also, as AI. SpaceFactory highlights:
Apart from being highly effective pressure vessels, they provide the greatest ratios of usable floor area to surface area and usable floor area to volume and diameter. Reducing surface area means using less material under less stress, reducing volume means reducing energy loads on mechanical systems and reducing diameter directly reduces structural stresses, especially at the base, where uplift forces will require anchorage into uncertain ground. Unlike domes they do not produce unusable overhead volume or unusable perimeter floor area.
AI. SpaceFactory has created their own material to build their cylindrical towers; a mix of locally mined basalt and renewable bioplastic (polylactic acid or PLA), which is processed from plants gathered on Mars. PLA can be made from corn starch, cassava roots, or sugar cane. However, the team hasn’t specified how many acres will be needed to grow enough plant material to build one of these cylinders.
It makes practical sense to grow the building material on Mars, rather than shipping the stuff, which would be incredibly energy-intensive and time-consuming. The team points out:
PLA has countless applications as an expendable material through the full mission timeline. Being a bioplastic, it has the added benefit of dual modes of in-situ manufacture: via the fermentation of carbohydrates by bacteria or via chemo-catalysis. On Earth, most PLA is derived from polysaccharides produced by plants. The same could be carried out on a future Mars settlement, where inevitable plant and other biological waste provide an opportunity to close material/ metabolic loops.
The team at AI. SpaceFactory has designed MARSHA to ensure that a human colony will have everything they need to thrive on the Red Planet. It has a joint dry lab and kitchen (although eating where you also experiment might be risky), individual cabins, ‘sanitation pods’, a hydroponic garden, and a ‘skyroom’ (dedicated for recreational uses, like playing video games, and exercise).
Outside of the habitat, tasks would include dusting the solar panels, maintaining the nuclear plants, and tending to the PLA-producing crops.
A separate competition from HP – called the Mars Home Planet Challenge – saw teams develop a variety of fascinating designs for a future habitat on Mars. The winning entries all used dome designs, so it will be interesting to see what kind of design is eventually preferred and lived in. Musk believes in setting up a permanent colony. He has said:
It will start off building just the most elementary infrastructure, just a base to create some propellant, a power station, blast domes in which to grow crops — all of the sort of fundamentals without which you cannot survive. And then really there’s going to be an explosion of entrepreneurial opportunity because Mars will need everything from iron foundries to pizza joints. I think Mars should really have great bars: the Mars Bar.
Terraforming Mars
If we want to make Mars a viable second home for us, then we will need to terraform it. Terraforming (which literally means “Earth-shaping”) the Red Planet would involve altering its surface and climate in order to make the planet – or at least large areas of it – hospitable to humans. It will, of course, be an extremely difficult enterprise.
Yes, trying to live in an environment which can kill you is a bit problematic. Without a pressure suit, the low pressure on Mars will cause a human to die within a few minutes. Exposed bodily liquids, such as saliva, tears, urine, blood and the liquids wetting the alveoli in the lungs will boil away. One astronaut was exposed to pressure below the Armstrong limit. He survived. But his “last conscious memory was of the water on his tongue beginning to boil”. Scary stuff indeed.
If we can raise the atmospheric pressure to a certain level, then pressure suits will no longer be necessary (although oxygen masks still will be). British physicist Martyn Fogg wrote in his book Terraforming: Engineering Planetary Environments (1995) that there are five challenges when it comes to terraforming Mars. And increasing atmospheric pressure is one of them.
It can be done by increasing the temperature of the polar caps. These are mostly made out of dry ice (solid CO2). By warming them by just a few degrees, we can make the solid CO2 into gas CO2. The gas will then cause a greenhouse effect, warming the planet and causing the ice beneath the surface to melt. This will cause Mars to have nearly 100% the atmospheric pressure of Earth. It will also create a suitable temperature for life, and create oceans and lakes.
But how do we warm the polar caps in the first place? There are a few ways this can be done. In Technological Requirements for Terraforming Mars, Chris McKay and Robert Zubrin suggest using giant orbital mirrors to reflect sunlight to the caps. Another solution is to heat them with nuclear reactors. Or we can create greenhouse-producing factories on Mars. There are all kinds of challenges posed by each of these solutions. But given the rate of technological advancement, meeting these challenges may be within our reach in the near future.
What’s promising, though, is that heating the polar caps would also tackle another one of Fogg’s challenges: increasing the surface temperature of the Red Planet.
Canadian geneticist Robert Haynes coined the term ecopoiesis, which is the process of making a planet more hospitable for primitive microbial life. Raising the atmospheric pressure and surface temperature of Mars will help achieve this. As well as make the Martian climate easier to explore by humans. But the remaining challenge of making the atmosphere breathable is a lot trickier.
The problem is that the air on Mars consists of 95% carbon dioxide, 3% nitrogen, 1.6% argon, and trace amounts of oxygen and other gases. On Earth, oxygen accounts for about 21% of the air that we breathe, with nitrogen accounting for 73%.
Mars simply doesn’t have enough nitrogen to support large-scale life. So we will need to increase the amount of nitrogen. However, Mars’ nitrogen is all stored in mineral form as nitrates in the regolith. It will require a massive amount of energy to free these reserves. It may be possible to introduce significant atmospheric nitrogen from ammonia-rich asteroids. But again, hurling these asteroids (in a controlled way of course) at Mars would be expensive in terms of energy.
Another one of the challenges presented by Fogg is reducing the amount of UV radiation on the surface of Mars. One way of reducing this harmful radiation is to introduce highly UV-resistant lifeforms, such as lichen, directly onto the surface. These organisms would release oxygen, which would form ozone in the upper atmosphere, and in turn, reduce the amount of UV radiation reaching the Martian surface. But as mentioned previously, the lack of nitrogen makes it difficult for large-scale organisms such as lichen to be able to survive in the first place.
We may never be able to fine-tune Mars’ climate to make it exactly like Earth’s. So the Red Planet may never support human life as we know it today. But that doesn’t mean a permanent human population can’t be sustainable. It just means we have to figure out ways to tolerate whatever conditions we create by terraforming Mars.
China has managed to turn desert into fertile land, which offers hope for successfully terraforming of Mars.
In 2002, China passed a law that aims to tackle desert expansion. Since then, China has been carrying out several projects, with one taking place at a desert in the north. North China’s Inner Mongolia Autonomous Region receives little (if any) annual rain and is characterised by scorching temperatures.
In response to this unfavourable environment for growing crops, researchers developed a technology – a paste – made of a particular substance found in plant cell walls. What these researchers discovered is that when this substance is added to sand, it can retain water, nutrients and air, all of which allow for the growth of vegetation. Zhao Chaohua, Associate Professor of Chongqing Jiaotong University, said:
According to our calculation, there are over 70 kinds of crops growing here. Many are not planted by us but they just grow themselves.
Using this technology is also extremely efficient. As Yang Qingguo, professor at Chongqing Jiaotong University, points out:
The costs of artificial materials and machines for transforming sand into soil is lower compared with controlled environmental agriculture and reclamation.
China also has ambitious plans. It plans to transform an additional 200 hectares of the desert – and possibly even 13,000 more in the next few years – into arable land. This is a truly breakthrough experiment. Being able to convert sand into soil means land that previously seemed hostile to life can now be made fertile.
It’s worth highlighting, though, that China is by no means the first country to carry out such an experiment. The Sahara Forest Project, a Norwegian company, has been developing cutting-edge food, water and energy technologies to turn the deserts of Qatar and Jordan into farms. As Smithsonian.com reports:
The plan: to combine solar thermal technologies with saltwater evaporation techniques, freshwater condensation and efficient production of food and biomass without displacing existing agriculture or natural vegetation. As desertification becomes an increasingly vexing problem around the world, this group of technologists is aiming for revegetation.
Perhaps something like the paste used to transform China’s deserts could be used to make the Martian surface arable. Another proposed method for terraforming Mars entails warming the planet. While the idea of subjecting another planet to global warming may seem like an insane thing to do, given the mess we’ve got ourselves into, global warming could actually be crucial to making Mars a habitable planet.
In order to make the surface of Mars fertile, it needs to be covered with water that is stable. Currently, as NASA researcher Michael Chaffin, underscores:
If you took a glass of liquid water to Mars and poured it out, some of it would freeze, and some of it would boil away, but none of it would remain liquid for very long.
Popular Science reports how global warming could offer a solution:
Theoretically, if we were able to pump greenhouse gases into Mars’ atmosphere, we could warm the surface of the planet enough for liquid water to be stable on the surface, as it was in the distant past (roughly 3.5 billion years ago). The thicker atmosphere would also provide enough pressure to help water remain stable.
One way this might be possible…is to manufacture super-greenhouse gases or perfluorocarbons (PFCs) in automated factories. These compounds would trap the heat from sunlight on Mars, without disrupting the planet’s fragile ozone layer or posing a toxic threat to human settlers.
Another possible solution is to use certain organisms – extremophiles, bacteria that can survive in extreme environments on Earth – to convert the Martian surface into arable soil. However, Imre Friedman, a microbiologist who proposed the idea, said:
I don’t think any of us alive today will see this happen. When the time does come to make Mars a more habitable place, the technology will be so different that everything we plan today… will be ridiculously outdated.
Indeed, while we can speculate about whether revolutionary paste, global warming or microorganisms will turn the Red Planet’s surface into farmland, we are so far away from achieving this aim that we cannot really predict what technology we’ll end up utilising.
Countries in the Arab world are also harnessing technology to transform the desert into farmland. Two Norwegian companies – Desert Control and the Sahara Forest Project – show how we can take some of the harshest environments on Earth and make it suitable for the growing of crops.
Norwegian scientist Kristian Morten Olesen, who founded the startup Desert Control, has patented a process that mixes very tiny particles of clay with water, which then bind to sand particles, making the desert fertile. He says:
The treatment gives sand particles a clay coating which completely changes their physical properties and allows them to bind with water.
This process doesn’t involve any chemical agents. We can change any poor-quality sandy soils into high-yield agricultural land in just seven hours.
Olesen’s Liquid Nanoclay (LNC) was trialled in the deserts of UAE. Two areas were planted with tomatoes, aubergines, and okra. Only one area was treated with LNC. Faisal Mohammed Al Shimmari, a local farmer, said:
I am amazed to see the success of LNC. It just saved consumption of water by more than 50%, it means now I can double the green cover with the same water.
The Sahara Forest Project (SFP), a Norwegian company, has managed to grow vegetables in the desert of Qatar at a similar rate to European farms. The Tunisian and Jordanian governments have also given the company permission to build facilities in the desert to grow crops. There are various challenges to overcome, however. Professor Heribert Hirt notes:
The problems are not dissimilar to doing agriculture on Mars. (Among) the biggest problems in the entire region of Northern Africa and the Arab countries are the dust and sand storms that constantly cover up solar panels and get into all machinery that is exposed.
He emphasises, though, that SFP is “worth the effort and will teach us more how to transform these vast regions of unused land back into agriculture.” It’s worth highlighting how Hirt draws a comparison between these efforts and the possibility of terraforming Mars. If these projects can successfully and reliably transform the desert into fertile land, then this adds hope to the goal of making the Red Planet hospitable to human life.
GMOs on Mars
We may need to get over our knee-jerk reaction to GMO crops, as they may be necessary to survive on Mars. The study of genetically modifying organisms so that they can survive on spaceships and other planets is known as space synthetic biology.
The harsh conditions on Mars present many challenges when it comes to growing food there. Space synthetic biologists are genetically changing organisms so that they can be more ‘space-worthy’. For example, organisms need to be resistant to heat and radiation. If the organisms astronauts bring with them can’t survive on Mars, then they may not be able to survive on Mars.
Lynn Rothschild, head of the synthetic biology programme at NASA’s Ames Research Center, has led a group who took genes from extremophiles and inserted them into E. coli to create hybrid organisms that can resist extreme pH, temperature, and dryness. They dubbed it the Hell Cell.
Amor Menezes of the California Institute for Quantitative Biosciences recommends in a report that we develop space-friendly microbes that can turn byproducts of wastewater treatment into food. While that may not sound too appetising, it is certainly a sustainable vision. Menezes highlights, however, that this food does have to qualify as “nutrient-dense biomass that supplements astronaut dry-food while being versatile in flavor and texture.”
The effects of microgravity on microorganisms will complicate efforts to engineer organisms for use in space. For a synthetic biologist, it would be a great achievement to engineer GMOs that can help produce food and oxygen, or serve as probiotics for astronauts. But these genetic programmes may be changed in the presence of microgravity, due to the organism’s natural stress response mechanisms. It is also incredibly expensive and slow to study this phenomenon, so it may be some time before new versions of life are built that can survive in space.
However, this kind of work is very important. And scientists are ambitious about their hopes for what GMOs can achieve when it comes to space travel and colonising Mars. Synthetic biologists think we could use GMOs to biomine the regolith for metals, produce biofuels, grow enhanced algae as food, replace medications that have degraded in cosmic radiations, and terraform Mars.
Indeed, the possible applications of GMOs are wide in scope and very promising. It seems that they are essential if we are to survive on Mars.
Getting High on Mars
The desire to get high is a part of our human nature. Just as humans want gustatory pleasure from food, we also want the pleasure that comes from altering our consciousness. We have consumed substances to change our consciousness for millennia. Every society all over the world does so in some form or another, for different reasons (e.g. recreation, religion, performance), and so a life on Mars without some drug will be a life that is missing something essentially human.
To meet this human drive on Mars, we need to figure out what drug will be the first to be cultivated and used. How might drug culture change on the Red Planet? For various reasons, it seems that cannabis is the preferred candidate, at least according to Mars Farm Odyssey, an international consortium of urban farmers, food entrepreneurs, NGOs, and biohackers.
This group is trying to find solutions to space farming, so that food can be grown on Mars. The alternative is shipping food to Mars, which is just not sustainable – it would cost nearly $1bn a year per person. The amount of resources involved in such a journey makes it extremely wasteful. But these like-minded scientists, engineers, and entrepreneurs don’t just have survival in mind. They want Mars to be a place for leisure and recreation as well. Which is why they believe cannabis could be grown as well.
At a meeting in Tel Aviv, Mars Farm held their first-ever workshops. Discussions focused on vertical farming, urban farming, and recipes for space travel and Martian life. One workshop looked at developing a citizen science kit that will crowdsource how particular plants grow, making it possible to build controlled ‘food computers’ that robotically create the climate and nutrients that a plant needs. Thieme Hennis, a Dutch researcher who attended the meeting, said:
With a complete model of the plant, and knowledge of these environmental factors (pH of the water, temperature, relative humidity, etc.) you would be able to predict the growth of a plant, and also steer the growth.
The group in Tel Aviv were also discussing whether beer or cannabis should be the preferred intoxicant on Mars. Kloosterman said:
We’d let a small craft beer system on board and we’d make beer from recycled urine, but cannabis is, by far, getting the first vote by me.
Cannabis will be the easiest to produce since we already know that it can be grown hydroponically. It will also be interesting to have a society in which alcohol features less prominently than cannabis. There will likely be fewer accidents, less violence and fewer health issues than if alcohol was the preferred Martian intoxicant. But there will also be some very hungry colonists. And so without a sustainable food system, being high on Mars will not be a very enjoyable experience.
