What dangers must we overcome before we can live on Mars? | Aeon Essays (2023)

Can humans live on Mars? The answer is amazingly simple. Can humans live in Antarctica, where temperatures regularly drop below -50°C (-60°F) and it's dark six months of the year? Can humans live under the ocean where pressure increases rapidly to crushing levels as depth increases? Can humans live in space where there is no air at all?

As the limits of our ingenuity, materials science, and chemistry have grown, we have gone from being able to tolerate only a narrow band of conditions to expanding our presence to almost every part of the world and now beyond. Even the most hostile environment we have ever encountered - the vacuum of space - had a continuoushuman populationfor more than two decades.

So why not Mars? If we can live in Antarctica, if we can live in space, then surely it's just a question of logistics. If we can get enough material onto the surface of the red planet, we might be able to survive - and even thrive - there.

But that "if" takes a lot of work. When we went to the moon, the astronauts had to carry everything they needed for their visit to their tiny, fragile lands. TheApollo missionsspent only between one and three days on the surface - and it only took three days to get to the moon itself. If a Mars-boundAstronautwill spend months in space just to get to the landing pad, spending only a few days on the planet will not satisfy. Every mission, even the first one, is bound to beplannedbe for months, and that increases thecomplexityof logistics enormously.

Mars is a particularly difficult planetto land on it. It's too far from Earth to remotely control a descent — on average, a radio signal is enough12 minutesto cover the distance – so everything has to be pre-programmed. A single error in the computer or in its inputs will result in a new and expensive crater, of which there have been many. And once the order to land has been given, there's nothing anyone in mission control can do to intervene - the time elapsing between that order and asafe landing, is known as the "seven minutes of terror".

The weak Martian atmosphere also makes landing difficult. It's thick enough that any spacecraft emerging from orbit needs a heat shield to keep it from burning up, but even the latest generation of giant supersonic parachutes struggle to provide any significant support in the thin air on the way down . What remains of the orbital velocity must be accounted for, or our landers will shatter on the frozen surface of Mars.

A giant silver rocket with everything the astronauts need for their months-long stay just isn't practical

Various methods have been used, but the most consistently successful has been the "Sky Crane," a disposable frame fitted with retro rockets that burn until it hovers a few feet above the surface. It then gently winds the lander down, disconnects its connecting cables, and then flies a safe distance away from its enginesruns out.

As expected, these calculations are very finely judged. Every pound of lander—the batteries, the solar panels, the science experiments—requires several kilograms of fuel in the sky crane. And every kilogram of fuel in the Sky Crane requires several kilograms of fuel on the rocket that will take it into Mars orbit. We'd send bigger, better landers to Mars if we could -- but rocketry is at its very limits when it comes to putting a rover the size of a small car on the ground. This has huge implications for conducting a successful manned mission to Mars.

Whilewe could dreama huge silver rocket slowly descending to the dusty red surface and containing everything the astronauts would need for their months-long stay, we find it just not practical. This rocket, and the even larger spacecraft required to get it there, will exceed our projected launch capabilities for decades, if not centuries. Planning a successful Mars mission - for a permanent presence on Mars - requires of uswork smarter, and take every advantage we can. This includes those that we can find on Mars itself.

Mars is a planet full of useful resources and specific dangers. On the plus side, if we choose our landing spot wisely, we don't have to take water with us. Water is heavy and there is nothing we can do to make it lighter. It takes up space and there is nothing we can do to make it smaller. And even with the best recycling facilities, the astronauts still need a certain amount of replacement water. However, there are many places on Mars where water is just in the form of icePartof the floor. Stick a shovel in the ground and half of what's picked up is popsicles. And we can use this water for all sorts of things, not just drinking. We can use it for chemistry.

We can break it down into its component parts using electrolysis. We can breathe the oxygen - this saves us having to fill up with air. And if we recombine it with the hydrogen, we have an explosive mixture that we could use as rudimentary rocket fuel. If we go one step further, we can remove the carbon from Mars' carbon dioxide atmosphere and synthesize hydrocarbons for better combustion.

This carbon dioxide is also vital for plant growth. Add water and a growing medium and suddenly supplementing our freeze-dried food packs becomes not just a possibility, it's an objective. Humans consume a lot of calories, but we also eat with our eyes. A side salad isn't just nutrition, it's a mood booster.

Then there's the stuff from Mars itself. That's what we can use as construction material: makebrickfrom it, or simply pile it up and over our existing structures. And we really have to, because life on the surface of Mars isn't easy.

The red dust has become a nanoparticle and poses a great danger to both us and our machines

Temperature is the most immediate. Mars is an average of80 millionKilometer(50 millionmiles) farther from the Sun, and its atmosphere is too thin to absorb the extremes of diurnal variations. Daytime temperatures in mid-summer can reach a balmy 21 °C (70 °F), but on the same day, just before sunrise, -90 °C (-130 °F) are recorded. Temperatures can drop enough to freeze carbon dioxide out of the atmosphere. The added insulation of several feet of Martian soil will be a welcome bonus.

Additionally, it helps with a long-term threat: radiation. The sun constantly spews out charged particles and high-energy light in the form of gamma and gamma raysX-rays.On Earth, and to a lesser extent on the Moon, we are protected by the Earth's large magnetic field, which extends into space and deflects the solar wind around us. Mars does not have such a magnetic field, and while surface conditions are not acutely life-threatening, they are every day astronauts spend on the Martian surfaceaccumulateRadiation damage 10 to 20 times faster than on Earth — not counting the occasional solar flare that squeezes a decade's exposure into a single event.

Burying the astronaut base underground is a relatively simple solution to this radiation problem. The same goes for building in a cave - volcanic areas of Mars are the sites of lava tubes that now form huge tunnels, with access through partially collapsing roofs.

The soil itself is toxic, rich in perchlorates. While these are a potential source of oxygen, perchlorates are water soluble: contaminated soil cannot be used as a growing medium.

Then there's the dust. Formed by hundreds of millions of years of continuous grinding of volcanic ash, the red dust has become so fine that even the weak Martian winds can carry it and keep it aloft for weeks. The dust has become a nanoparticle - with an average size of 3 μm (one 10,000th of an inch) - and poses a great danger to both us and our machines. Dust from living quarters could hardly be ruled out: Astronauts would bring it in from outdoor excursions, and even with zealous measures – washing, vacuuming, anti-static windows and air filters – it would become part of the air we breathe and the food they ate. In addition to the perchlorates already mentioned, there are other carcinogenic compounds and the damage fine-grain rock dust can cause specifically to the lungs and eyes.

We already havelosta rover in the dust coating its solar panels. The more complex the machines we use, the safer we need our seals and finishes to be. Maintenance as well as spare parts to support this regime would have to be strictly adhered to.

So How can we do that? We have parameters set by the number of crews we send, how long they plan to stay initially, and what they intend to do once they get there. We need to plan to house, water and feed them, and then bring them home - and if we intend to do anything other than a one-time visit, we need to keep the long game in mind: what kind of infrastructure can we build, that will be useful in the future?

Breaking the problem down into manageable chunks is by far the most viable approach. What we learn from such incremental efforts—and what we have already learned—can help us work our way through the various elements we need to conduct a successful and sustainable Mars mission.

We must prioritize a safe landing without burdening the descent with the weight of food, fuel, air and water

The first stage would be increasing our capabilities in low Earth orbit. A multi-month trip to Mars requires the largest spacecraft we've ever built, and almost certainly something that can't be lifted in a single launch. It must be built in space using similar methods to the International Space Station. Fuel, along with everything needed to sustain life for the long journey, has to be shipped off Earth - twice as it comes back. The descent vehicle will be a separate part of the ship, while the main part will remain in Mars orbit.

The second stage would be to send supplies to the designated landing area. If we can, we should send robotic self-erecting modules. This would ensure there is a safe place for the newly arrived astronauts and allow us to prioritize a safe landing without adding the extra weight of food, fuel, air and water to the descent phase. And that way, we wouldn't have to commit astronauts to the long and arduous journey to Mars until we know there's enough equipment to support them. If a rocket is lost - more than one is statistically likely to be lost - we simply send another one.

One of the pieces of equipment we would send ahead would be an ascent module, an empty ship that can not only land on Mars but also refuel itself from the Martian atmosphere, ready for return to the transfer ship in orbit.

TTo be clear, none of this is risk-free. As you know, an alternativeNetworkwas extradited to US President Richard Nixon in advance in 1969Apollo 11Landing covering the failure scenario. Although our careful preparation has made success more likely, there are still situations from which it would be all but impossible to recover. The main cause of this is how long it would take for us to react to the unforeseen.

Supply chains are one of the most underestimated andmisunderstoodFactors that make up a modern economy. We are very used to being able to order anything from anywhere and have it available within days if not hours. Manufacturers maintain just-in-time inventory with their suppliers, and retailers promise near-immediate delivery. Behind these storefronts lies a fantastically complex web of communications, transportation, inventory control and staff. We only notice it when it fails.

Almost everywhere on earth is networked. Vital medicines, microchips, engine parts and even living organs for donation are moved seamlessly between countries and continents. But there are places where that's not true, and they give us our first glimpse of what challenges a Martian colonist might face.

Antarctica, despite our technology,remainsone of the most isolated and inhospitable places on earth. Almost everything that is needed - apart from air and water - has to be shipped or flown in, over long distances and not without risk. Heavy seas, thick ice, a storm, an extreme cold snap: you all see food and fuel stuck on a dock or on an airstrip. Antarctic bases do not operate a just-in-time supply chain because when that supply chain is inevitably disrupted, people can die. Planning for these disruptions means you need to carry and store far more than is typically required. Those of us who aren't preppers will balk at the amount of food it takes to feed a single person for a few months: the winter population of the Amundsen-Scott base just at the South Pole,is 50

Of course, food can always be rationed. The heating can be reduced to one or two heavily insulated modules. There are backup generators and a doctor on site, as well as a modern satellite-linked communications suite. The scientists are supported by a full team of electricians, plumbers and technicians who work around the clock to maintain the base's infrastructure, identify problems before they become critical and use their expertise to offer workarounds.

The risk of death - from hunger, cold, suffocation, accident, disease, infirmity - must be accepted

None of these have prevented problems from occurring. In particular, when the base doctor falls ill and needs an operation, as happened twice, the doctor operates himself. In both cases, a medical evacuation was not possible due to the bad weather conditions and the distances involved. Some permanent bases still insist that staff have their appendix removed prior to arrival.

Now imagine this would happen on Mars. A fully operational base, in the most favorable position, with multiple redundant infrastructure maintained by shifts of highly motivated and trained engineers, is still in a far more precarious position than any Antarctic base today. A coup de grace to airdrop urgent medical supplies in Antarctica from New Zealand's South Island is difficult but possible: the travel time, once everything is in place, is just a few hours. Meanwhile, if the launch window is friendly, Earth to Mars will take nine months. New generations of space drives will inevitably reduce that, but nothing can be done to eliminate the vast distances between the two planets. at best,56 millionKilometer(C35 millionMiles). In the worst case, when Earth is on one side of the Sun and Mars on the other,400 millionKilometer(C250 millionMiles).

Without a doubt it would be the longest supply chain in history, culminating in the harshest environment we have ever encountered. Even in the sailing age, the journey from England to Australia was faster.

As a doctor on the first Mars mission, you don't have to decide which medicines and bandages and surgical equipment you take, but which you don't. What can you do without? Space and weight are limited. If you are the engineer, how will you choose between this critical spare part and that critical spare part? Of course, you could ask the mission planners to send one - or two - of everything. But how doable is that given everything that has happened before? At some point, enough is too much. The risk of death - from hunger, cold, suffocation, accident, illness, disease - must be accepted.

As with all pioneers, the heaviest burden falls on those who go first. You will be the most uncomfortable, the most precarious, the most vulnerable. Those who follow after, if not easy, certainly have it easier. The infrastructure of the original base is to be expanded as long as the earth believes in the project. What is certain is that Mars will be completely dependent on Earth for decades to come. But how would a Mars colony grow toward independence? Can we see that far ahead?

Manufacturing is a key technology here: not only the usual but vital supply of spare parts, but also the vital chemicals. Specially tailored medicines, dietary supplements and plant nutrients give the colonists a degree of security;3D printerWith a vast library of models, one can begin to deal with the physical, while the biological components can be conjured up through automated synthesis machines.

Another cornerstone of a more self-contained Mars would be thatSettlersthemselves - and in particular their education. Necessity is often the mother of invention, but Mars would be a very strict disciplinarian. A Martian colonist would have to devote a significant amount of time to learning. The level of technology required to maintain a functioning colony would be high and staff numbers limited by the food and air available. Since each expert is in two or three different areas of knowledge, a tragic accident need not turn into a crisisfor all.

The highly precarious nature of life on Mars will inevitably give rise to new onessocial moresAndCodesOf the behavior. Far from being rugged individualists, Martians rely on each other in a highly interdependent manner throughout their lives - and they will reflect this in both their relationships and their laws.

How different colonists will become from the mother planet remains to be seen. But an independent Mars would not be a copy of any Earth society. It would be terrifying and deeply alien.

The Red Planet: A Natural History of Mars (2022) von Simon Morden istpublishedby Pegasus Books.

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