In my job, I spend a lot of time writing about humans living on other worlds. So, you can imagine how talk of doing it for real piques my interest. However, there are more challenges to life on the moon or Mars than simply showing up in a space suit and planting a flag.
If our astronauts are planning to stay for any length of time, they will need living space. In The Martian, they assemble a prefabricated hab unit made from durable industrial canvas. While tough and capable of shielding inhabitants from some of the harsh conditions on the surface, this hab unit is essentially a high-tech pressurised tent. It provides a shelter from the weather and a space where our astronauts can spend time without cumbersome pressure suits, but it can only provide a limited amount of protection from other dangers.
On Earth, our atmosphere and magnetic field shield us from solar radiation, but the moon and Mars possess neither of these protections. Human beings on the surface of Mars would be exposed to an average of around 230 millisieverts per year.
To put this into perspective, the UK’s Ionising Radiations Regulations 2017 sets the upper limit for an adult as 20 mSv in any calendar year, and only 6 mSv for a child. This means that without protection, our would-be settlers would be absorbing almost twelve times the recommended upper safe limit every year. In addition, NASA’s Mars Odyssey Probe detected occasional solar events that delivered 20 msv to the surface of Mars in a single day.
Obviously, any humans intending to stay on Mars need some form of shelter from this radiation. In his book The Case for Mars: The Plan to Settle the Red Planet and Why We Must, Robert Zubrin proposes digging shelters into the ground, using soil as a shield against radiation. This would obviously require the use of heavy machinery to excavate the necessary caverns, and careful engineering to ensure these underground spaces remained stable and habitable.
The lack of water and air on Mars means these underground bases will need to recycle their air and water with an astonishing level of efficiency, and employ solar power to heat them against the intense cold. Apart from occasional and limited trips to the surface in space suits, our settlers would be confined to a subterranean life similar to being aboard a submarine or spaceship for an extended period of time, and bringing with it all the attendant psychological pressures such confinement entails.
Of course, science fiction writers have proposed some wild solutions to these problems. In his epic Martian trilogy, (Red Mars, Green Mars, Blue Mars) Kim Stanley Robinson depicts a multi-generational effort to terraform the red planet, using a number of methods in concert, from huge boreholes used to release heat from deep in the planet, to the deliberate crashing of ice asteroids in order to increase the amount of water in the atmosphere (something also suggested by Isaac Asimov in The Martian Way). Robinson also depicts a giant mirror in orbit that greatly increases the amount of sunlight reaching the surface—a slightly more feasible approach than Arthur C. Clarke used in The Sands of Mars, where he suggests the creation of an artificial sun!
Elon Musk has suggested using nuclear weapons on the polar regions of Mars, vaporising the frozen water and carbon dioxide in order to create an atmosphere that will trap heat and provide some protection from solar radiation. However, a joint study by the Northern Arizona University Flagstaff and the University of Colorado Boulder has concluded that there just isn’t enough ice on Mars to achieve this, even if it was all injected into the atmosphere.
Even if such a plan was feasible, the lack of a magnetic field means the solar wind would quickly strip the new atmosphere away. Unfortunately, the only way to create a magnetic field would be to somehow jumpstart the planet’s molten core, causing it to rotate—a project of truly gargantuan scale and something that’s probably way beyond our capabilities.
In his 1976 novel, Man Plus, Frederik Pohl takes a different approach altogether. Rather than try to change the planet to suit our needs, he puts forward the idea of artificially changing human beings to suit the harsh environment, creating a race of cyborgs able to endure life on the cold, airless surface.
The inescapable truth is that Earth is the best home we have, and if we’re going to spend a fortune and a generational effort changing a planet’s atmospheric composition to make it habitable, maybe we should start with this one.
Gareth L. Powell is an award-winning author of science fiction. He can be found online at www.garethlpowell.com
Hard hat mounted air curtain adds layer of protection
Something similar was used by miners decades ago!