Living in the most inhospitable place to date will surely be an amazing feat of science and engineering.
I was disappointed by my last article's coverage of actual Mars habitats (a single lousy paragraph) and I wanted to include something more. I have also tried a different, I hope, friendlier approach, in the scope of attracting more readers from all backgrounds.
I will be your guide in this endeavor, trying to compile an easy to read Mars Colonization Handbook. Previously in our imaginary journey we have learned how to launch, orbit, achieve a Mars Insertion Orbit, and land (safely). We have talked about power generation, producing water, oxygen and nutritional sustenance and even fuel to return to earth without having to carry the return fuel. We have discussed about radiation protection and today we will explore the technology required to make us live on Mars.
A rendering of a possible Mars habitat, called Ice Home, credited to NASA's Langley Research Center
Features of the ideal Mars Habitat
- A lightweight structure, ideally placed on the surface to keep the explorers' or colonists' mental health positive.
- Inflatable structure would further reduce the cargo space occupied
- Using local materials for thermal and radiation insulation would reduce its launch mass from Earth
- Natural light would offer a great reduction in energy consumption
- Portability should also be taken into consideration as we might discover other areas of interest and relocation might be necessary at least in the beginning phases
- Excellent radiation protection during Solar Flares or Solar Storms
- Easy access to the habitats and ideally a way to have an oversight of the habitats from orbit or even from Earth
Habitats in the lava tubes
We will first explore the basic habitat solution, inside already formed lava tubes. A lava tube is either created by lava flows close to the surface which solidify the outlying crust and erupts at the point of least resistance or by lava making its way through the crust in a long period of time, creating huge networks of caves and canals in its search for the weakest point in the regolith. The low gravity also plays a big role as the resulting lava tubes can be up to 10 times bigger than on Earth. This creates huge chambers and large connecting canals.
A study made by University of Padova and the University of Bologna compares the lava tubes on Earth, Mars and the moon and comes to the conclusion that whole cities could be fitted inside.
The difficulty would be finding such lava tubes in the first place, as the current technology is insufficient. Scouting of the lava tubes will have to be done IN-SITU, using drones and rovers. Advantages of the lava tubes as habitats are the fact that if we settle in a vast network of lava tubes we would be able to develop a cheap transit system, with minimal additional protection against radiation or weather. A healthy and fast transit system will be paramount for the mining operations and for the scouting of new areas.
Underground, the temperature will also fluctuate less, putting even less stress on the materials and the associated welding points. This translates into cheap infrastructure. By using LED lighting with intelligent sensors, sufficient lighting could be used when it is needed. The surface could be used by mining rovers and energy sources and little exposure will be necessary. Habitats could be drilled into the walls and stacked on top of another due to the limited gravity. Materials used could be very light and very easy to ship and by using the technology available to us since the early metal age, we could easily build habitats in great numbers. We have a history of building underground, one of the best examples is Kaymakli Underground City, in Turkey, built in the 8th–7th centuries B.C.E. We have since advanced technologically quite a bit :)

Kaymakli Underground City, a huge underground complex with individual homes and an integrated ventilation system.
By using the local regolith and minerals we could actually "plug" and isolate a section of the lava tubes and then coat the permeable walls with mortar and even try to pressurize the interior. All of this is done using the local materials and the technology available to us even before the industrial age, so imagine what a team of highly trained engineers might be able to do given enough time and robotic help. Also don't forget that any engineer could lift up to 3 times more than on Earth. This is something that the ancient people couldn't do in Turkey.
Now think of even more help for the explorers. Think about locating an enclosed lava pond or even an active lava flow under the regolith.
My imagination can run wild. Heat could be used for centralized heating. Steam generators could supply energy. Light is also produced by the lava, even if it's not in an appropriate wave length. Plants could grow there. In time, maybe the gasses and the ash could be used as prime substances for fertilizing. The implementations are limitless.
Let's not forget that the other big venture of Elon Musk is a boring company. The useful type of boring, that is. Imagine how a reusable, long lasting, boring machine that would not need to be discarded after use could do to the martian soil, or under it.
Habitats on the surface
But we are used to living under the sky, some of us could never live underground, or maybe until we find the perfect lava tubes we would need to live on the surface. Is it possible?
NASA says it is. By using a lot of the studies put together they have designed a habitat on the surface.
By using ice and composite materials their Langley Research Center have designed a habitat protected from the worst of conditions. A lot of teams worked together to propose and subsequently win the NASA Centennial Challenge.
By 3D printing of a large inflatable torus and building and filling a composite material shell with water that is then frozen (naturally by the temperatures of the planet) even before the first astronauts land, by simple robots, the concept works by using the aforementioned (in my last article) benefits of hydrogen and water radiation protective effects from solar flares and cosmic rays. In addition, the structure backs as life support backbone, due to its water storage, that could be used by the IN-SITU system to generate Oxygen, sustain plant growth and even help to generate the fuel needed for the return. This protection, while should not compare to the underground habitats, is enough for most of the missions.
But their ideas are not limited to this. All of the materials are transparent to a certain degree, this means that natural light can flow inside and be used for the decentralized farming activities inside of each habitat and has positive implications over the mental health of the dwellers. These materials will be sturdy and will have a life of "many years" despite the harsh environment, corrosive gasses and substances and wind-shear.
Each habitat comes with an airlock which doubles as a garage for allowing rovers to be serviced without the bulky suits on the astronauts.
The third phase of the competition is open now, if you want to participate you can do so here. The winning team wins a $2 Million prize. A lot of Steem could be powered-up with those :D
Conclusions
Research is abundant here and it shows us that living on Mars is not at all impossible, despite factors like microgravity and psychological isolation which I will try to cover in a future article. It remains to be seen if the protection is adequate or if a mix of habitats will be used. Keeping the astronauts in surface habitats and then moving them when increased solar activity or solar flares ensue could have a beneficial effect on the economy of building materials there and thus reducing the cargo needed to be shipped from Earth.
Notes and further reading:
Images of the Ice Home are sourced via watermark to "NASA Langley/Clouds AO/SEArch"
https://www.nasa.gov/press-release/nasa-selects-six-companies-to-develop-prototypes-concepts-for-deep-space-habitats
https://en.wikipedia.org/wiki/Caves_of_Mars_Project
https://en.wikipedia.org/wiki/Martian_lava_tube
http://www.marsicehouse.com/habitat/ - the latest version of their award winning home:
https://vimeo.com/142099027
https://www.valentinasumini.com/mars-city-presentation
https://www.reddit.com/r/space/comments/3b0huh/how_much_thermal_insulation_for_a_mars_habitat/
http://www.imagineeringezine.com/e-zine/mars-makeshelter.html
http://blogs.discovermagazine.com/fieldnotes/2013/07/15/the-challenges-of-climate-control-in-a-mars-habitat/#.WsMr-YhuaLU - this is a report from the simulated Mars Mission - HI-SEAS.
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20060048561.pdf - another wonderful study that I didn't cover a lot of - about printing and repairing habitats on Mars.
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