Humans have looked out at the stars and planets for millennia, but it is only with the advent of flight that the dream of leaving our planet has become even remotely possible. The first human space flight by the soviet citizen Yuri Gagarin in 1961 was relatively quickly followed by the US moon landing in 1969. However, progress since then has been confined to near Earth orbit. The Cold War, which spurred the space race, had ended by the late 1970’s and commercial usage of satellites and near- earth exploration became the priority. This is compounded with the fact that the technical difficulties of reaching another planet are indefinitely greater than flying to the moon. Yet this has not stopped space enthusiasts from dreaming of a day when we will land on another planet, the most obvious choice being Mars. Mars is the second closest planet to Earth in our solar system, and the most earth-like, therefore it is thought to be the easiest stepping stone in our quest to become a multiplanetary species.
When the orbits of Earth and Mars are closest, the distance between the two planets is 34 million miles, 1000 times the distance between Earth and the Moon. To travel this distance, we will need an extremely powerful rocket, and massive amounts of fuel. This is where our first problem arises. The only model of rocket we have ever built that would have been capable of carrying us to Mars – the Saturn V no longer exists. This rocket was the tallest, heaviest and most powerful rocket that has been brought to operational status, and only 13 were built. They were used to bring us to the moon, and the last was launched in 1973. Today, no rockets exist that could provide us with a return journey to Mars. In order to do this, we would need reusable rockets (which have not yet been invented). The more fuel we use, the shorter our travel time will be. There is, of course, investment in other modes of transportation. A vasimr engine could reduce travel time to 5 months, while antimatter could reduce it to 45 days. However, it will be decades at least until some of these technologies will be on the market and ready to use.
Alternatively, SpaceX, a rocket company founded by Elon Musk is in the process of designing ‘Super Heavy’ (also known as BFR), a rocket system that is hoped to be fully reusable, designed to carry up to 100 people on interplanetary flights. This rocket, alongside the ‘starship’, one intended to reduce flight time to anywhere on earth to under an hour, are some of the world’s current greatest underway inventions. Considering that SpaceX has, in 10 years become a company worth $25 billion, and has in only a decade, managed to become the world’s biggest rocket launching company, with over 50 successful missions, it is amazing to think what it may be able to do in the next decade.
The distance to Mars gives rise to another issue- the lengthy amounts of time that astronauts will have to spend in space. Getting to Mars will take roughly 240 days. Surviving this long in space is a challenge for any astronaut and its dangers are varied. The first is its impact on mental health. Despite the fact that all astronauts are heavily psychologically tested, depression and attention deficit are conditions that astronauts are likely to have to face. This is mainly due to the massive amounts of time they will spend staring at a black void. A recent study observing a group of people in isolation as the base of a volcano has determined that to avoid mental health issues such as depression and anxiety, astronauts will have to be kept busy with physical activity and work for the majority of the day.
Astronauts will however also be faced with many physiological dangers. The gravity on Mars is 38% of Earth gravity, at 3.7m/s2, compared to ours at 9.8m/s2. Throughout the journey to Mars, the gravity inside the rocket will be in micro-g’s (microgravity). The long-term effects of weightlessness for a journey of 7 months are likely to include the atrophy of the heart and muscles, balance and eyesight disorders, as well as a reduction of aerobic capacity and a slowing down of the cardiovascular system. When on Mars, the human body will have to adapt to small amounts of gravity again. The return journey will be even harsher, as astronauts will not have experienced our full gravity for several years. It may be possible to counter this problem by slowly reducing gravity in the spacecraft and then increasing it again on the return journey, but the technology for this is still questionable. Other dangers include those of disease. Growing evidence shows that prolonged periods in space can have a detrimental effect on the human immune system making astronauts more vulnerable to disease. In addition to this, outside dangers such as cosmic and solar radiation could cause cancer, dementia and impaired vision. To prevent these, engineers are in the process of designing suits and shelter that will be able to withstand heavy radiation. However, the dangers of stray rays piecing them will always be there.
Now that we can understand some of the dangers and issues that astronauts and technicians will face to get us to Mars, how soon will it actually be?
Elon Musk believes that SpaceX will be able to bring the first people to Mars by 2022. That is in just 3 years. Its objectives for this mission will be to confirm water resources, identify hazards and to build the initial infrastructure that will be needed to live on Mars for a significant amount of time. They optimistically believe that a second mission with crew and cargo aboard, will land in 2024.
NASA on the other hand is slightly less optimistic. They plan to take advantage of the point in a 15-year cycle when we will need to least energy to make the journey, and get to Mars by 2033. President Trump himself has issued a mandate urging NASA to do this. However, for NASA to fulfil its aim it will require an estimate of over $500 billion. Currently NASA’s annual budget is $19.5 billion. It would take many years for NASA to accumulate the funding for such a mission. This has led rise to the debate between whether it will be national or even international organisations such as NASA that will be the first to land humans on Mars, or whether it will be privately owned companies such as SpaceX, Virgin Galactic and Blue Origin, who will achieve this feat. National organisations lack the funding a mission of this scale would require, and therefore it is private companies that are launching a new space race. This race is not greatly international. Many companies that aim for interplanetary travel are based in the US, and they do not compete for dominance in achieving a goal, but rather for customers. Their aims include commercialising space travel in orbit, making life on other planets possible, and visits to the moon.
Once we have reached Mars, there is one more challenge we must overcome – how to survive there. The basic requirements for human life on earth are food, water, and shelter. Living on Mars requires the same things, and one more - oxygen. The Martian atmosphere is 100 times thinner than ours, containing 96% carbon dioxide. This is not breathable. For humans to survive on Mars, we would need to produce our own oxygen, and we would not be able to step outside without a spacesuit. Carrying enough oxygen from Earth to Mars to support around 6 people for 4 years would be impossible. Luckily, Michael Hecht a scientist at MIT has developed an instrument called MOXIE, a specialised reverse fuel cell that converts CO2 into O2. This instrument has been selected by NASA to accompany Mars 2020 (a rover being sent to Mars next year to aid the Curiosity rover). It is believed that a system like MOXIE, may in the future be able to provide oxygen on a larger scale that could support a mission to Mars.
The next challenge astronauts living on Mars would face is temperature. The average temperature on Mars is -630C. At the height of summer at the equator, it might reach 210C, while at night lows can reach -730C. This would make it impossible for astronauts or even future colonists to go outside without a highly insulated suit (this is forgetting the problem of Mars’s extremely low pressure at 0.6% of Earth’s).
Getting water on Mars will be another issue. Water is an extremely heavy substance and it would therefore be impossible to bring it from earth to our destination. Although Mars may look barren, it is not. Only a few cm under Mars’s red surface lies a layer of permafrost. Rovers have discovered that the Martian soil contains up to 60% water, and in addition to this, large amounts of ice are concentrated at its north and south poles. However, melting this will not be necessary as in 1998, a dehumidifier was invented that would be able to draw all the water needed to live on Mars from its atmosphere.
With possible solutions for obtaining water and oxygen on Mars, other key challenges revolve around shelter and food. Although it may be possible to grow 20% of settlers’ food requirements hydroponically in greenhouses, 80% of food will have to be dried and brought over from earth. The issue of shelter is possibly easier to solve. Initially astronauts are expected to live in their landers, and inflatable pressurised buildings. Later, it is thought that they will be able to build bricks out of the Martian soil, or live in caves and lava tubes.
Surviving on Mars looks as if it may be achievable. But will living in restricted shelter, without being able to go outside and breath fresh air really satisfy us? Although we currently see going to Mars as scientific exploration, some believe and hope that we will one day be able to live there. While Mars is the most earth-like planet in our solar system, the differences between the two planets are significant. The variety of life, nature and beauty on earth simply does not exist there. Scientists say that it may be possible to terraform Mars, that we could heat the dry ice on the poles to thicken its atmosphere, we could sublime ice with solar sails to flood the planet with water, and we could create a water cycle with rain and snow similar to that on Earth. Yet these theories are not proven. For now, we must focus on getting to Mars, living there will be a separate issue.
By Caroline Utermann