Moving To Mars: Mankind’s Next Home
By: Blake Ives
The ultimate future of the human race is unknown, but some day there will be a need to
leave our beloved home planet, Earth. Any number of events could be cause for interstellar
colonization; a global-extinction-sized asteroid on a collision path with Earth, our sun’s eminent
expansion into a red giant as it nears the end of its life, global nuclear fallout, or even the
invasion of hostile alien species.
Regardless of the reason we need to leave the planet,
interplanetary colonization will be essential for human survival. The first stepping stone to the
preservation of the human race is life on Mars. Living on Mars has been the premise behind
generations of science-fiction works including Outpost Mars by Cyril Judd, Arthur C. Clarke’s
The Sands of Mars, and Kim Stanley Robinson’s Mars trilogy: Red Mars, Green Mars, and Blue
Mars. As technology continues to advance, the concept of colonization is becoming less of
science-fiction and more of a reality: however, there are still many obstacles that must be
overcome if humans are to live on the “Red Planet” someday.
This article will present and discuss key factors, obstacles, developments and headways,
and strategies for colonizing Mars.
Why Mars?
When considering galactic colonization, a common question among theorists and
scientists is not, “Should we colonize?” but rather, “Where should we colonize first?” There are
plenty of reasonable options when it comes to our “cosmic backyard,” the solar system: Venus,
the planetary body most similar to Earth in composition, size, density, and one of our
neighboring planets; Europa, one of Jupiter’s moons which contains liquid water and a thermally
active core that could easily harbor biological development; the Moon, the closest planetary body
to Earth, and one that we have set foot on before; and Mars, another neighboring planet and one
that may lie within the “Goldilocks Zone” where astronomical conditions are appropriate to
harbor life. While there are pros and cons to colonizing each body, public interest in Mars is
high. Since public interest often affects funding, Mars is a front-runner for a future human
habitat.
Mars
attracts
attention
because it is the most publicized of
our fellow solar-satellites. Often
advertised as being similar to our
beloved Earth itself, Mars is a
reasonable
consideration
for
scientific inquiry. Mars and Earth
do in fact have a lot in common.As
seen in Figure 1, the Martian day
(24 hours 39 minutes 35 seconds)
lasts nearly the same as Earth’s
[1]; Mars has an axial tilt, causing
Figure 1: Comparison of basic Earth and Mars properties
Credit: NASA
seasons [1]; the polar ice caps and
soil contain deposits of water
𝑚
[2][3]; gravity on Mars’ surface is 3.711 𝑠2 , roughly 38% of Earth’s [4]. But, while those
similarities are enticing criteria for a retirement home, there is much dissimilarity that would
make living on Mars quite difficult.
Obstacles We Would Face:
While Mars is one of the closest planets to our home world, and shares many favorable
characteristics, there are quite a few critical factors that need consideration before launching to
another planet. These factors range from alien environment to physical and psychological wear
to cost and permanent living arrangements. All of these issues are essential to colonists’ survival
and must be carefully evaluated when considering colonization missions.
Martian Environment:
Life on Mars would be vastly different from the day-to-day ease it is here on Earth. The
largest measureable difference is the environment. The Martian atmosphere is predominantly
carbon-dioxide gas, CO2, which is poisonous to all life on Earth in large quantities. On Mars,
carbon-dioxide composes roughly 93% of the atmosphere, whereas on Earth carbon-dioxide
makes up roughly 0.04% [4][5].
The high percentage of carbon-dioxide in Mars’ atmosphere poses a poisonous threat to
any normal earthling. This problem has been approached in a number of ways. One method is
to transport dark lichen, algae, and bacteria to the Martian surface. These organisms would
convert CO2 into small amounts of oxygen, produce carbohydrates, and raise the planet’s
average temperature, −63℃ (−76℉), by reducing the planet’s albedo radiation1 and trapping
more thermal energy [4][5][6]. An alternative method is to import mass quantities of hydrogen
gas into the atmosphere. Using known gas properties, the hydrogen could react with carbon
dioxide to produce methane and water via the Sabatier reaction2 [7]. The water and methane
produced could be easily used by colonists to maintain their habitat and daily lives.
Other environmental differences include the thin atmosphere and lack of a strong
magnetosphere3. The Martian atmosphere is 6.36 millibars of pressure on average, one hundred
sixty times thinner than the average atmosphere on Earth’s surface, 1014 millibars [4][8]. To
1
Albedo radiation refers to the amount of incident radiation from space that is reflected off a planet’s surface back
into the atmosphere or space.
2
The Sabatier reaction, given by the equation (𝐶𝑂2 + 4𝐻2 → 𝐶𝐻4 + 𝐻2 𝑂) is a process underwhich carbon dioxide
and hydrogen gas combine with energy under pressure to produce methane gas and water.
3
A magnetosphere is comprised of an electromagnetic field often produced by a rotating planetary core.
survive such low atmospheric pressure
on Mars colonists would require
pressurized
suits.
A
strong
magnetosphere, will partially shield a
planet from solar, albedo, and cosmic
radiation. As seen in Figure 2, Mars
has a much weaker magnetosphere
compared to Earth. Since Mars does
not have a strong magnetosphere, the
surface of the planet experiences high
levels of radiation [9].
Exposure to
high levels of radiation can cause
radiation
sickness
or
amongst humans.
even
death
Figure 2: Solar wind hitting Venus (top) Earth (middle) Mars
(bottom). Earth has a strong magnetosphere and therefore is
more protected from radiation from space. Credit: ESA
The Radiation Assessment Detector (RAD) on the Curiosity rover measures radiation levels
on the Martian surface.
According to Hassler [10], RAD is designed to determine both
atmospheric composition and radiation levels on the Martian surface. Although RAD data is not
yet available for comparison, it is certain that current space suits, which are designed for high
radiation - low pressure environments, would need to be modified to account for the change in
radioactive exposure.
Human Health:
Another consideration for colonization would be psychological and physical health. The
most efficient and safest journey to Mars takes roughly seven months [11]. Being confined in a
small spacecraft with 3-5 people for seven months, then spending years disassociated with life on
Earth, combined with the stresses of adjusting to life in an entirely new terrain could be mentally
exhausting. The European Space Agency (ESA) and the Russian Academy of Sciences Institute
for Biomedical Problems (IBMP) conducted the Mars500 experiment, a simulation of the seven
month journey to and from Mars, to analyze psychological effects of long term isolation. Six
“marsonauts” were locked in a capsule near Moscow, Russia for 520 days to simulate the trip to
and from our red neighbor. According to the ESA,
“In addition to being helpful in determining psychological aspects of spaceflight, this
research has been invaluable in determining radiation hazards and the adaptation to
weightlessness, as well as in the development of life support systems” [12].
Living on Mars would certainly have physical detriments as well. Tests aboard space
stations, as well as astronaut health exams post spaceflight, have determined that human bodies
deteriorate rapidly in microgravity. According to Joyner, long-term exposure to microgravity
causes decreases in bone density, cardiovascular efficiency, and muscle mass [13]. However,
since these tests were conducted in microgravity while orbiting Earth, it is not certain how the
human body will react to Martian gravity.
Price:
Space travel is not by any means cheap. One of the most recent missions to the “Red
Planet”, the Mars Science Laboratory (dubbed “Curiosity”), cost NASA roughly $2.5 billion
[14]. Prospective costs of colonizing Mars start in the hundred billions of dollars for research,
design, construction, and habitat stabilization. However, the cost diminishes significantly if
astronauts sent to Mars would not be returning home. Providing a “one-way-ticket” to Mars
would cut all costs of materials, fuel, and construction of a Martian launch vehicle, as well as
transporting those materials to the planet itself.
The introduction of the private space sector will also reduce the price of future missions
to Mars. According to SpaceX founder Elon Musk, “an advanced, reusable system could allow
individuals seeking round trips to Mars for just $500,000” [15]. Groundbreaking organizations
like SpaceX, MarsDrive, and MarsOne are advancing space technologies to make spaceflight
both more affordable and more accessible.
Energy:
One problem with space travel is the production of electricity and power. Spacecraft
power supplies can range from nuclear reactors to pre-charged batteries; however, the most
commonly used energy source for medium to long duration space missions is solar power. Solar
power, or the production of electricity through photovoltaic cells, has often been considered
expensive and inefficient. Fortunately, continuous research has made the technology cheaper, as
well as more energy effective. Between early 2008 and April, 2012, the cost of photovoltaic
cells decreased nearly 75%, from $3.88/W to $1.01/W [16]. To determine the most efficient
method for converting light into usable energy, solar power companies are also experimenting
with cell composition and layouts. Companies like TetraSun and AltaDevices have created cells
that absorb visible light with 20%-30% efficiency [17]. While these companies focus on visible
light, research is being conducted at centers across the United States to include other ranges of
the electromagnetic spectrum. It has been estimated that solar cells could improve up to 80%
efficiency by including other areas of the spectrum [18].
With the continual decrease in
production cost and increase in efficiency, solar energy will likely be a main source of power for
future Martian inhabitants.
Another mechanism that will be essential to Martian life is the fuel cell. Fuel cells are
devices which create electrical energy through means of chemical reaction. Due to increased
carbon emissions on Earth, ongoing studies at Princeton University are attempting to combine
carbon dioxide (𝐶𝑂2 ) with hydrogen and oxygen to produce hydrocarbons for fuel [19]. The
main problems the research team faces are funding and gathering large quantities of resources.
With the lab’s current product efficiency, to match the oil industry’s power output the team
would require 8,500 moles of 𝐶𝑂2 per barrel of oil consumed in the United States [19]. While
such quantities of carbon dioxide are difficult to obtain on Earth, the Martian atmosphere is 93%
carbon dioxide, making the fuel cell a viable power source. If the team can make the process
affordable, 𝐶𝑂2 powered fuel cells could decrease the concentration of the poisonous gas in the
Martian atmosphere while also providing a steady power supply for future colonists.
How will we survive?
Companies, corporations, and individuals have been suggesting detailed plans for safely
and cheaply forming a colony on Mars for many years. The first theory I ever heard was that of
my seventh-grade space camp counselor, “First, melt the polar ice caps and glaciers with lasers
from satellites. Then, pot plants all around the planet so they can turn the carbon dioxide into
oxygen for us. Lastly, put up an umbrella to block the radiation.”
To his credit, many theories for terraforming Mars recommend melting the polar ice caps
to produce useable water; however, melting the caps would release trapped 𝐶𝑂2 molecules and
increase the toxicity of the Martian atmosphere
even further [20]. A more practical concept would
be to avoid the harsh environment by living
underground in caves or empty lava tubes. These
underground caverns would shield inhabitants
from the dangerous levels of radiation and cold
temperatures [21].
Another, highly publicized,
concept is to live in a giant structure on the surface
that supports an artificial environment, known as a
biodome. A biodome on Mars would be similar to
John Allen’s Biosphere 2 experiment performed at
the University of Arizona [22].
The biosphere
used in the experiment was an structure fit for selfsustainability and contained all necessary elements
for human survival. However, biodomes on the
Martian surface would still be subject to higher
levels of radiation than living deep within the
planet.
Despite the higher radiation threat,
versions of surface habitats similar to the biodome
Figure 3: Artist renderings of possible Martian
colonist habitats.
(Above) Use of lava tubes and caves [NASA]
(Below) Surface biodomes [MarsFoundation]
have been adopted by most organizations like SpaceX, MarsDirect, MarsOne, and NASA’s Mars
Design Reference Mission, who are seriously interested in long term manned missions to Mars,
due to the practicality and ease of construction on the surface compared to that of underground
habitats.
Summary:
While many great challenges, ranging from environment to psychological stability to
habitat construction, must be overcome before humans can colonize Mars, many technological
feats have made moving to the “Red Planet” closer to a reality. Research and advancements in
space technology, human safety, and alien environments are only the beginning of a long journey
to land humans on another planet in our solar system. With innovative organizations like NASA,
SpaceX, MarsDirect, and MarsOne leading the way in space exploration, living on Mars may no
longer only be the dreams of science-fiction novelists anymore.
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