It’s 2095, and the first colonists are about to depart for Mars. It’s a time of anxieties, fears and colossal excitement. There are health concerns, both physical and psychological. There’s a lot of technology to rely on, and a lot that could go wrong.

The goodbyes are tearful; there is the acknowledgement that many, if not all, of these people are leaving Earth for the last time. But above all, there’s an unparalleled sense of adventure. What will life be like for the first colonists on Mars? How difficult will their daily lives be? And what hardships and risks will they face?

There are three key challenges facing potential Mars inhabitants. The first is getting there; the second is creating a sustainable environment after arrival and the third is the long-term survival and development of the colony. Choosing the people who will go to Mars is a fine art.

It takes at least six months to reach the red planet, so finding people who can live in cramped spaces for that length of time, and get on well with each other is essential. “This takes a particular type of character; people who are easy-going and don’t get wound up easily,” says Sue Horne, head of space exploration at the UK Space Agency.

Additionally, there is a much harsher radiation environment to travel through than anything faced by the Apollo astronauts. “If there’s a solar flare, for example, you’d have to go into a confined, protected part of the spacecraft to prevent excessive radiation exposure,” explains Horne. “With long flights in zero gravity, the immune system is also suppressed and there will be weight loss too. So there are extensive health issues being faced, and that’s before you even get there.”

On arrival, the risks intensify as Mars is such a harsh, radioactive environment – or to put it more precisely, “a high-energy particulate radiation environment”.

“You have to have a pressurised habitat, with stored oxygen,” says Horne. Due to the incoming high-energy particulate radiation, this habitat is unlikely to be the kind of geodesic dome familiar from speculative articles about Mars landings.

Many, if not all, long-term Mars residents will be explorers by nature

“I don’t think the colonists will be in domes. Unless you invent a new material to protect you from radiation, those domes won’t work.”

Instead, the reality of a Mars colony for Horne is likely to be a cave environment. “This would require a vehicle to push soil over the habitat, cover it to a considerable depth and protect it from radiation.”

Harsh environments and slim pickings

What will everyday life on the colony be like? “Rather like an agrarian farm at the turn of the century,” says Professor Cameron Smith, Anthropology Faculty member at Portland State University. “Some isolation, and lot of concern with the health of the crops.”

Many, if not all, long-term Mars residents will be explorers by nature. “Some will choose not to explore much; others will want to spend a lot of time outdoors, exploring further and further away from their homes, on foot or using wheeled vehicles. All of course while wearing pressure garments, which will have to be very simple, robust and field-maintainable – unlike the space suits we have at the moment.”

Being a Mars colonist will not, by any stretch of the imagination, be a romantic occupation. The things we take for granted will be hard to come by. Consider just some basics of everyday living – what do you do for food and drink?

“Mars soil is quite toxic,” says Horne. “The answer will be to grow greens using hydroponics; it won’t be practical to continually transport food from Earth.” Some experiments of growing vegetables in a Mars-like environment have already been attempted; the results have not been spectacular, but there’s perhaps 80 years or so ahead to perfect this.

“Otherwise, you’d have to take dehydrated food with you, and regular two-year arrivals from Earth – there is a two-year ‘window’ when missions are possible – could bring more basic supplies.”

Perhaps contrary to earlier expectations, getting a water supply wouldn’t be the hardest problem faced by the colonists; there are two potential sources. There’s a huge amount of frozen water under the surface of Mars, so if drilling equipment can be transported, accessing it is a distinct and effectively limitless possibility.

But there’s an even more straightforward source, which is to use water recycling. “On the International Space Station today, the astronauts get the majority they need from water recycling,” Horne says. “Very little is lost. You simply recycle everything.”

Purpose and enterprise

A key question to ask is, why go to Mars at all? Dr Joel S Levine, a NASA senior research scientist for over forty years and now research professor at the Department of Applied Science, College of William and Mary, says there are several key reasons why colonising Mars is a vital endeavour.

“Becoming the first two-planet species may eventually ensure the survival of the human race should the Earth experience a catastrophic event,” he says. Secondly, the potential for finding life on Mars – likely to be bacterial – “will provide new insights into our understanding of the biochemistry and molecular chemistry of human life and will provide new insights into the treatment and cure of human diseases.”

Becoming the first two-planet species may eventually ensure the survival of the human race should the Earth experience a catastrophic event

Most of all, it is the very human urge to explore that will make a Mars colony likely. If the risks can be overcome, there will be people willing to put themselves through the dangerous and gruelling journey for an equally gruelling life on Mars.

There are valuable social effects back home too. Levine said: “The human mission, with daily television broadcasts back to Earth, will excite the general public and will stimulate youngsters to pursue careers in science, technology, engineering and mathematics.”

Relationships and everyday life

The first colonists will not only be geologists and biologists, but also farmers, builders, electricians and doctors. Once the colony has been safely established, a different set of issues becomes apparent – the maintenance and development of the colony.

Keeping the greenhouses going for food; keeping the water and oxygen-producing systems going and keeping the homes pressurised. “These alone will keep people busy,” says Smith.

The first colonists will not only be geologists and biologists, but also farmers, builders, electricians and doctors

But human life will carry on very much as it does at home. “Between the work, people will get together and have parties, find romantic partners and get married.” At this point, the colony will start to feel more like a community. “Once the daily routines of technical maintenance are done, people will spend a lot of time in recreation.”

Even so, there will be psychological challenges to overcome when living in an environment so different to Earth. “Some people will have a hard time and find it’s not what they expected; but most who go will be highly motivated to live this kind of life,” Smith continues.

“For those who love working with their hands and exploring outdoors, it could potentially be an ideal life.” Despite the constraints, from this different perspective Mars offers huge freedom.

It’s true to say that with one third of Earth’s gravity, Mars poses considerable physical challenges. “We don’t yet know how reproduction works there, or tissue development in the embryo,” says Smith. “This is a big physiological issue that needs to be sorted out.”

For the continuation of the Mars colony, it’s not absolutely essential that people reproduce; those two-yearly missions from Earth could bring new arrivals for as long as needed. But the more established the colony becomes, it’s inevitable that people will want to have children.

The first person born on Mars will have the kind of fame that attached to the first heart transplant patient, and the first test-tube baby. Or, indeed, the first person to walk on the Moon.

Dangers for long-term survival

The main risks the colony will face are again comparable to early agrarian farmers. “Communicable diseases, which can be resolved by quarantine,” explains Smith. “And crop failure, offset by stored food supplies.”

A hazard not faced by our agricultural ancestors is the danger of a spacesuit or pressurised rover vehicle leaking while outdoors. This would be ‘a big, quick catastrophe, but I think they will be extremely reliable by this time, as they are just too important.

“The whole point of going to Mars is to explore its surface, not to live inside.” So being outdoors with reliable equipment will be a key element to get right before the colony is launched. “Modern diving gear almost never fails, and much of its reliability is due to its simplicity,” observes Smith.

There is also an ethical question about long-term colonisation. “We now have evidence that methane is in the atmosphere of Mars,” says Levine. “On Earth, almost all of the methane (99.9%) is produced by living systems. Not little green men, but microscopic life below the surface or at the surface.”

This isn’t solid evidence that there is – or was – life on Mars, but suggests it is likely, because methane is “a gas that on Earth is biogenic in origin – produced by living systems.”

For Horne, this creates a moral dilemma. “Have we got the right to affect that ecosystem – if there is one? There’s also the potential issue not only of us damaging the ecosystem, but if there is life on Mars, is there anything that could transmit to humans; diseases we don’t know about?”

Shine on, Martian moon

So how likely is it, realistically speaking, that the colonisation of Mars will take place? Is it a pipe-dream, a sci-fi fantasy that will never really happen? Or is it a practicable possibility?

“We will have people going there eventually,” Horne asserts. “However, I’m not quite so convinced about colonists. It’s a long way off, if at all. Even a round trip is going to be difficult, all things considered.”

Solid predictions, based on evidence rather than hope, very much rely on the levels of investment that governments (and, increasingly, wealthy individuals) are willing to make. “It all depends on money. If you invest as much as the US invested in the Apollo missions, it would happen sooner rather than later. But I think it’s a minimum of 40 years from now to go at all, and a colony would be much, much later than that.”

Smith is more optimistic. “I think there will be international human-crewed explorations in the next couple of decades. They will be like the first to the Moon or the South Pole – long, risky and expensive, with some catastrophes.

“But that will not stop anyone, and in fact will only increase the will to succeed. In the end, as with the invention of the aeroplane, someone will make it.”