As concerns around our future on earth grow the interest in colonising other planets is gaining momentum. Opinion is divided on whether settlement of Mars is a science fiction dream or a necessity, however, a number of organisations (including NASA, ESA, Boeing and SpaceX) are researching the viability of colonisation and taking steps toward a permanent human presence on the red planet.
Opinion is divided on whether settlement of Mars is a science fiction dream or a necessity, however, a number of organisations (including NASA, ESA, Boeing and SpaceX) are researching the viability of colonisation and taking steps toward a permanent human presence on the red planet. NASA chief Jim Bridenstine has recently reinforced his claim that the space agency will be able to land humans on Mars in the decade 2030, potentially as early as 2035 (1) and the Mars One programme has been operating since 2012 aiming to establish a permanent human settlement on Mars with departure of the first crew scheduled for 2031 (2).
Of all the planets in the solar system, Mars appears to be the most habitable and has a number of resources that could be extracted and exploited. Mars also has some reassuring similarities to Earth:
- The Martian solar day is similar in length to Earth’s: 24 hours, 39 minutes and 35.244 seconds (3)
- Mars has a surface area that is almost equivalent to the amount of dry land on Earth
- Mars has an axial tilt of 25.19°, which is similar to the axial tilt of Earth at 23.44°. This means Mars has seasons similar to Earth, although they will last longer because the Martian year is equivalent to around 1.88 Earth years
- The presence of water ice has been confirmed on Mars through observations by NASA’s Mars Reconnaissance Orbiter, ESA’s Mars Express and NASA’s Phoenix Lander
Despite these appealing properties the Martian environment is harsh and inhospitable compared to Earth, and there are environmental challenges such as unsuitable air (mainly CO2 with only around 0.1% O2), lack of gravity (Mars has only 38% of the Earth’s gravity) and a cold climate, which averages at ‑63⁰C. The atmospheric pressure on Mars is also far below the Armstrong limit at which people can survive without pressure suits.
For colonisation of Mars to be successful significant innovation will be required to advance technologies beyond what we know today. Despite the challenges that moving to Mars would present there are already some technologies on planet Earth (and within CPI!) that could help humans in their mission to become intergalactic…
To be able to colonise Mars we will need a renewable source of energy, such as solar energy. Solar or photovoltaic cells convert light energy directly into electrical energy, and are one of the world’s fastest growing energy technologies with clear potential as a power source option on Mars. The use of photovoltaic solar arrays on the surface of Mars would present a number of challenges, including freezing temperatures, lower solar intensity due to the greater distance of Mars from the sun and the dust in the atmosphere which would settle on the arrays and also modify the solar spectrum reducing its intensity. Development of photovoltaic technologies for colonising Mars will require robust devices with high conversion efficiencies, solar cell dust abatement and low-temperature electrolyte cells (4). Solar energy is thought to be a much better choice than wind energy in the Martian environment (5).
Plants would be a vital part of successful Mars colonisation, providing healthy food, removing toxic carbon dioxide from the air and producing life-sustaining oxygen. The presence of plants would also transpire water vapor into the air that could be condensed and used as drinking water. The soil on Mars is likely to be very poor for growing plants, so if humans were to colonise Mars we would need to use alternative agricultural methods, for example hydroponics. Hydroponics is the science of growing plants without soil and instead feeding them using mineral nutrient solutions containing a variety of elements dissolved in water, and it can be used as part of a vertical farming system that uses of layers of plant trays with a water and light source. The plant scientists at NASA are researching the use of hydroponic methods for growing plants in space, and the Kennedy Space Centre’s Mars Base 1 Botany Lab have recently completed an experiment to grow tomato plants hydroponically (6).
Microorganisms are critical to many of the processes that sustain life as we know it, such as digestion of food, supporting plant growth and waste decomposition. To successfully colonise Mars we would probably have to take beneficial microorganisms with us. The Martian environment can be considered harsh by human standards; however, extremophile microorganisms exist that tolerate or even thrive in extreme environmental conditions such as freezing temperatures and low pressures. Some scientists have controversially argued that Earthling microbes should be the first to go to Mars as pioneering colonists, and begin seeding the Martian microbiome to form the basis of biological life (7).
Mammalian cell culture
Given the environmental differences between Earth and Mars traditional animal agriculture as we currently know it will likely not be possible, and meat would be in scarce supply or not available at all. With advances in mammalian cell culture technology scientists are now figuring out how to grow meat in bioreactors, so Mars colonists will still be able to have a bacon sandwich.
3D printing is a versatile method that could help to make life on Mars possible, and has the potential to be used to create anything from houses through to personalised pills and clothes. NASA recently held the ‘3D-Printed Habitat Challenge’, a $3.15 million competition to build a 3D printed habitat for deep space exploration. The project was designed to advance the construction technologies that will be needed to create sustainable housing solutions for Earth and space (8).
So what do you think? Is moving to Mars a dream or delusion?
Before we pack our bags ready to move to “Planet B” there is still much research to be done, and the advances that are made in helping to get us to Mars will likely be useful on Earth too.
3. Badescu, Viorel (2009). Mars: Prospective Energy and Material Resources (illustrated ed.). Springer Science & Business Media. p. 600. ISBN 978 – 3‑642 – 03629‑3. Extract of page 600
5. Delgado-Bonal, Alfonso & Martín-Torres, F. J. & Vázquez-Martín, Sandra & Zorzano, María-Paz. (2016). Solar and wind exergy potentials for Mars. Energy. 102. 550 – 558
7. Jose V Lopez, Raquel S Peixoto, Alexandre S Rosado, Inevitable future: space colonization beyond Earth with microbes first, FEMS Microbiology Ecology, Volume 95, Issue 10, October 2019, fiz127