Will There be Cities on Mars?

A lot goes into a building’s design and construction. Engineers labour over each single detail for weeks or months, applying a science that we’ve refined brick by brick over the course of many years. …what if we took this industry off the Earth? Many people still think of permanent human settlements in space as science fiction, but we don’t realise how close we are to making this a reality. Buildingspecifier.com Editor Joe Bradbury discusses:

It’s no secret that Tesla’s Elon Musk has his eyes on the skies. He expects to transport one million people to Mars by launching three Starship rockets every day and generating “a lot of jobs” on the red planet. Musk has repeatedly stated that he is “very convinced” that SpaceX will land humans on Mars by 2026.

Prior to Christmas, Elon revealed that he has a new timeline for his big Mars project — and it’s sooner than you might think. “I’ll be surprised if we’re not landing on Mars within five years,” he told Time Magazine last year. Musk, the 50-year-old SpaceX founder and CEO has big plans for the Red Planet: namely, a self-sustaining city with solar-powered hydroponic farms where humans can permanently live, 34 million miles away from Earth.

Obviously, to achieve this we will need to achieve some impressive architectural feats, pushing the boundaries of what construction is capable of. 3D printed projects, automated systems, and construction technology will all be needed facilitate building on Mars.

What would the role of “space architect” entail? How can we take what we have learned as an industry on planet Earth and build upon it in extreme, hazardous, alien environments? Where does space construction intersect with terrestrial construction?

Space construction

Space construction, sometimes known as ‘off-earth construction,’ is a very difficult task in and of itself. The absence of gravity and the inapplicability of physical rules as we know them on Earth will undoubtedly raise new challenges for even the most experienced architects and specifiers.

Lack of atmospheric pressure, high levels of radiation, extreme temperature changes and alterations in gravity levels render most typical construction materials and procedures obsolete, thus making the process of construction difficult, to say the least. The lack of pre-existing services and infrastructure on Mars, such as electricity, water, and waste treatment, will also present concerns. With this in mind, several organisations and research centres have already begun devising innovative solutions to overcome these unique problems.

A need for new methods of construction arises

Following the declaration of Mars as our closest habitable planet, missions to colonise there have sprung up in abundance from a number of countries in recent years. Reputable organisations have been tirelessly striving to develop the most practical and practicable suggestions for living on the Mars, including mind-blowing designs for the building of habitable spaces that can endure the harsh conditions without compromising the quality of life for the inhabitants.

The Mars Ice House was a winning proposal for one of NASA’s habitat design challenges, recognising water as one of the key building components of human life. The design is comprised of two 3D-printed structural ice domes with living space running through the centre in the shape of a vertical lander, utilising in situ materials for a more sustainable design. While the construction and materials have been chosen to maximise thermal comfort and defend against the severe environment, further information about the building’s more technical aspects, such as electricity distribution and ventilation, have yet to be released.

AI Space Factory’s MARSHA is another interesting habitat concept. The construction is enabled by in situ resource utilisation – the concept of employing indigenous Martian materials to assist human exploration rather than earth-manufactured things – with sustainability and self-sufficiency at the forefront of this endeavour. The construction is a four-story dual-shell vertical tower housing laboratories, leisure rooms, and an in-house garden. Power and data inputs from an external source, as well as sanitary pods, have all been factored in.

Innovative solutions are necessary

NASA recently revealed their ability to synthesise a polymer called acrylonitrile butadiene styrene (ABS), a plastic that could be used to make numerous construction materials off Earth, during one of the many experiments undertaken on-board the International Space Station (ISS). ABS could be used to 3D print construction components in space, offering a potential long-term solution for building a new life for humanity on what was previously known as a “dead planet.”

Made in Space’s Archinaut One, a system that combines 3D printing and robotic arms to produce and install huge structures in space, is another new answer to space construction. The Archinaut is supposed to be able to receive digital files from Earth and ‘print’ necessary buildings with extreme precision, albeit it is still in the testing phase. Candarm, CSA’s space crane, is one of the older and more perculiar pieces of space gear. The Candarm was built on normal earth-cranes and might potentially contribute considerably to automated space-construction. It is currently mounted to the ISS and effectively executing maintenance procedures.

The issue of energy

Currently, solar power is the primary source of energy for most space missions. This has led to the installation of Li-On batteries alongside the photovoltaic system on the International Space Station to power the station’s functions when it is not in direct sunlight. To protect occupants from excessive temperatures, the station also has an Active Thermal Control System.

However, although a number of robotic probes sent to the explore the Martian surface have successfully utilized solar arrays for their power needs, such an approach would have trouble scaling to support human habitation. The principal concern with using solar power to support a mission is intermittency: solar panels only provide power when there is sunlight. This is a familiar problem on Earth, and a major obstacle to wider integration of renewables into the grid. The intermittency problem on Mars is more pernicious: enormous global dust storms envelop the planet typically once a year from 35 to 70 or more Martian days (sols). These dust storms tend to have an opacity, or optical depth, of at least 1 – meaning that the solar flux at the top of the atmosphere is attenuated to less than e-1 = 0.37 (37%) of its original value when it reaches the surface. In addition, because Mars is farther from the Sun than Earth is, it already only receives roughly half the average solar irradiance. This intermittency introduced by multi-month dust storms, combined with the usual diurnal oscillation in solar flux, would necessitate a considerable amount of energy storage.

Nuclear power is an attractive alternative to solar for several reasons. Its power output is constant in time, meaning less risk of prolonged power shortages that could prove hazardous to a human crew. It also weighs less per nameplate capacity than does solar when considering a Mars operating environment – a 2016 NASA study found that about 18,000 kg of solar power generation equipment would be needed to match the output of a 9000 kg fission system.

The night time temperature on Mars as measured by the Opportunity rover reach as low as -98°C with diurnal temperature variations of up to 100°C, so even a temporary power loss in such an environment could quickly become life-threatening as the heating systems fail. This presents another advantage of nuclear power: even in the event of an electrical fault, the passive heat from the reactor or radioisotopes could be used to warm the habitat.

In summary

Despite its early origins in science fiction, space settlement is becoming significantly more feasible and is rapidly becoming humanities next attainable aim. While there is still a long way to go, technological improvements and a surge in interest in the topic suggest that we may soon be designing buildings intended for extra-terrestrial use.

Finally, the idea that humanity is looking for a “Plan B” planet perhaps reveals the sheer magnitude of the pending environmental catastrophe on Earth. Perhaps this is one of the most important lessons we can learn from all this. After all, technology would have to work so hard to provide on Mars what already exists on Earth in abundance. Perhaps we should all learn to treasure it. Would we even need a plan to preserve our species from extinction on another planet if we modified our lifestyles here on Earth? Perhaps not…