Summary

The following is a design of an envisioned city on Mars capable of reaching population of 1 million people by mid-22nd century. Its design focuses on characteristics that will make it practical, vital and sustainable. As a pioneering large settlement, the design of this city will greatly differ from possible designs of future cities created after mankind has well established its presence in space. It will develop through three major phases defined by the achievement of four milestones:

• City founded milestone - City is founded as a small colony
• Science and tourism phase - Period of developing science and tourism projects
• First space elevator milestone - The first space elevator is built. It will boost the transport channels to the surface of the planet
• Real estate phase - Period of city expansion and the development of attractive marketplace for real estate on Mars
• First industrial factory milestone - The first industrial zone in orbit is built. It will boost the industrial potential of the city
• Industrial phase - Period of developing manufacturing power. It will make the city self-sustaining and autonomous
• Population of 1 million milestone

The design of the city is based on four key characteristics:

• Economic attractiveness - while Earth in 21st century is seeing the limit to its population and fierce competition over natural resources, the city on Mars will offer businesses healthy economic growth through access to fast-growing population and untapped resources
• Development roadmap - the identity of the city will evolve around a sequence of major milestones in its development - like building the first space elevator and the first industrial factory in space. This identity will attract the right residents to join the city and be part of its development
• Service platform - the city will provide a platform for services for the needs of its residents and businesses. It will make it easy for businesses to quickly start and scale their operations. It will also enforce regulation over all services to ensure they are safe to be consumed by the residents
• Modular infrastructure - the infrastructure provides basis for the logistics in the city through an assembly of standardized reusable modules. These modules are easy to replace when damaged and easy to relocate when the city needs to adapt and evolve

We will describe these through the interaction of three participating groups:

• Governor - the organization that initially founds the city and then runs it
• Residents - the people who live and work in the city
• Businesses - the service companies that supply the residents with everything needed to sustain and improve the quality of their lives

Economic attractiveness

The first city on Mars and its design will be shaped by the forces that lead humans settle on the planet. This design assumes the major force to be economics and we will start its description by looking at the projections of the relevant drivers of world economy in the near future.

Natural resources and population growth on Earth

The world has been experiencing exponential economic growth in the last decades with advances in technology and high standard of living. Despite the many threats to the economy (like financial crises, climate changes, depleting natural resources, social inequalities, etc.) businesses and consumers are used to this growth and are expecting it to continue. The economic growth, as measured by world GDP per capita, is projected to continue to grow but many analyses on the future of economy describe the increased effort required to maintain it, partially due to the effects of over-population. The increasing population on Earth and its increasingly demanding way of living will burden the access to the limited sources of energy, water and food.

Cost of living will increase in the following decades and will contribute to the slowdown of world population’s growth rate. Projections show that by year 2100 the growth rate of human population will get back to its levels around year 1900.

(Source: https://ourworldindata.org/world-population-growth)

Since population growth is a key driver of economic growth, the limited growth of population will also limit the economic growth on Earth. The world economy will bear the characteristics of a saturated market with high competition for the same base of consumers resulting into limited profitability and limited growth potential for the businesses.

Natural resources and population growth on Mars

While the economy on Earth will face over-population and saturated markets, the economy on Mars will have different challenges and opportunities. Mars is neither populated, nor developed. However, it has huge potential in land to populate, natural resources to extract and better access to Space and its resources. The major barriers to untapping this potential for population and natural resources can be removed with advances in technology. History shows high tech advances follow Moore’s law which reflects the observation of exponential advancements of certain technologies. Therefore, it is reasonable to assume that our abilities to expand our economy on Mars will grow exponentially, doubling every few years or decades.

Founding a city on Mars with even mediocre standard of living will unlock population growth rate like that of average Earth cities. Our proposed design will aim for relatively good standard of living with growth rate following the envisioned four milestones of development of the city:

• Annual growth rate of 20% from 2030 to 2050 with science and tourism as main source of income. The population will grow from 10 to 1000 residents. This period will bear the highest population growth rate. We will later describe the drive behind this growth that makes it realistic
• Annual growth rate of 10% from 2050 to 2100 with real estate and services as main source of income. The population will grow from 1K to 100K residents
• Annual growth rate of 5% from 2100 to 2150 with services still being the major source of income but now supplemented with manufacturing. The population will grow from 100K to 1M residents

As a result, the first city, or network of cities, will reach a population of 1 million by year 2150. This population will participate in the economy and will, by itself, attract businesses.

Natural resources on the surface of Mars and in space near the planet will also become easier to harvest. Although in the beginning heavy machinery will be expensive to transport to the planet, advances in technology - lighter materials and cheaper transportation - will gradually lower the costs for opening and operating extraction sites for natural resources. In contrast, on Earth the cost of running similar sites will continue to grow due to competition over resources and environmental concerns such as pollution hazards.

In addition, the gravity of Mars is only about 38% of that of Earth and it is situated 50% closer to the edge of the asteroid belt which makes it an excellent candidate for an asteroid mining hub with competitive advantage over Earth.

We can conclude that, during the following century, there will be a great contrast between Earth and Mars considering population growth and access to natural resources. Population growth on Earth will slow down, while that on Mars will grow exponentially. Access to natural resources on Earth will slow down, while it will grow exponentially on Mars. This conclusion suggests that at a given point in time Mars will become a very interesting investment opportunity and that early investors will gain advantage over laggers.

Economic development of a city on Mars

The design of the city proposed here will follow an interesting path of economic development. According to the three-sector model of economics the main focus of societies will shift from the primary sector (extraction of raw materials) through the secondary sector (manufacturing) to the tertiary sector (services). The model classifies intellectual activities and knowledge-based activities in the quaternary sector as an extension to the model.

The city on Mars will, however, follow a reversed path by starting almost entirely in the quaternary and tertiary sectors. Within the first few decades after its foundation its main livelihood and source of income will be from exporting science and tourism. Only after the first milestone - introducing the first space elevator - will it become sufficiently affordable for various businesses and individuals to self-fund their journey to Mars so that the critical mass of residents and services can reach the point for the tertiary sector to dominate the economic activities. Later, after the second milestone of building the first industrial factory in space, the secondary sector will gain momentum as the city will become capable of producing a rich variety of goods. Finally, the city will build the needed industrial power to develop the extraction sites for it to become net exporter of raw materials.

The share of economic sectors will evolve in the following way:

The design of the city on Mars deliberately supports this path of economic evolution and the city founder will have the responsibility to maintain it because it will ensure that GDP per capita for the city will start relatively high and will remain high, which will be an important factor for attracting businesses and residents.

Return on investment for the city founder

The city will be driven by three groups - the governor, residents and businesses. The city founder will possibly also be the first governor to run the city. The governor organization will have a few responsibilities that we will describe further. A major responsibility will be to maintain the economic viability of the city. This will include building the city by the design and managing the different phases, most importantly the first phase “Science and tourism” which will require a lot of financial investment and entrepreneurial skills until the city gains momentum to transition into the next phase.

The city founder will need to either provide or contract:

• Pipeline of science projects - for revenue
• Pipeline of tourists - for revenue
• The minimum set of services for life support and basic needs - shelter, air, water, food and waste, energy and heating, communication - through the service platform we will describe later - for supporting the science and tourism activities

The following calculation presents the scenario where the city founder provides and funds all minimum services. The calculation spreads all investments starting from a 10-year period before the city is founded. Capital and operating expenses are split in categories research and development (R&D), production, transportation, maintenance and operations with the following assumptions:

• Research and development activities start in 2020 (which is 10 years before the planned date of city founding)
• The population starts with 10 residents in 2030 and grows to 1000 residents in 2050
• The city founder provides the six life support services - the set of minimum services in the service platform
• Yearly spending of 200 million USD per service per year for research and development
• Service equipment is produced on Earth with progressively increased capacity amounting to 120% of actual population in the city
• Cost of service equipment starts at 50 million USD per resident per service and is reduced by 10% per year due to technological advances from the output of research and development
• Weight of service equipment is 10 000 kg per resident per service and is transported to Mars at 500 USD per kg
• Yearly maintenance expenses of service equipment are 20% of its production cost
• Yearly operating expenses and supplies for the service equipment is 100 000 USD per resident per service
• Scientists in city are 20% of population
• 3 active projects per scientist per year
• Yearly revenue of 25 million USD per active scientific project
• Tourists in city are 20% of population
• Revenue from one tourist year starts at 25 million USD in 2030 and falls by 20% year-by-year

This high-level calculation shows that the city founder will reach positive cash flow around year 2045 and will break even 10 years later. Net expenses before the point of positive cash flow top at 4 billion USD per year which could be a manageable investment for a joint venture by a group of dozens interested large enterprises that wish to capture the first mover advantage in a new Mars economy.

Development roadmap

The design of the city will follow a roadmap of four major milestones that will define three distinctive periods of economic development:

• City founded milestone - The city will be founded as a small colony with 10 residents
• Science and tourism phase - The period following the foundation of the city. During this period the city will develop unique opportunities for scientists and tourists to support its growth. The population will grow to 1 thousand residents.
• First space elevator milestone - The city will build its first space elevator as a highway connecting the surface of the planet and planet orbit
• Real estate phase - The period following the opening of the space elevator. During this period the city will develop real estate and services market attracting people to its unique lifestyle. The population will grow to 100 thousand residents.
• First industrial factory milestone - The city will build an industrial zone in orbit using its network of space elevators to access space and planet surface
• Industrial phase - The period following the opening of the industrial factory in space. In this period the city will specialize in manufacturing exploiting the characteristics of space and will support its growth through exports. The population will grow to 1 million.
• Population of 1 million milestone - The city will become a true city of our civilization with unique cultural, social, economic and political footprint

2030: City founded. Science and tourism phase

After 10 years of preparation, the city will be founded in around 2030 with the infrastructure and staff to support science projects and tourism. It will start as a small colony with 10 residents and will gradually grow adding infrastructure, habitats and service buildings as more residents move in.

The governor will play a critical role in this period. The governor organization will be responsible for balancing revenue generation, rate of immigration and city construction activities.

The governor organization will sell seats for scientist and tourists in advance allowing enough time for building the city to accommodate them. Scientists will be limited to 20% of the total population. Tourists will be limited to another 20% of the total population. The remaining 60% of the population will be providing infrastructure maintenance and services to the scientists and tourists. During this period, the governor organization will carefully select these people such that they are likely to settle permanently. It will look for young people, couples, with complementing skills.

The governor organization will also lay the foundations of the service platform that will ensure residents can meet their needs and businesses can easily start and grow. However, the city will be still too small as a market to attract businesses. The governor organization will develop it by contracting the businesses needed for the basic needs of the residents - for shelter, air, food, water, heating, electricity, communication.

The income of the city will rely on the science projects and tourists. The city will re-invest part of the income in scaling the infrastructure and staff but will still need additional capital investments to reach population of 1 thousand. A portion of the investment will be used to build the first space elevator.

2050: First Space elevator. Real-estate phase

The city will build its first space elevator in around 2050. A space elevator is a type of planet-to-space transportation system that permits vehicles to travel along a cable from the surface directly into space or orbit without the use of large rockets, where the cable is held up from above by centrifugal forces. We do not yet have material for such a long cable that can withstand the gravitational forces of the Earth, but a space elevator is feasible on Mars because we have such material for its weaker gravitational forces.

The elevator will be a “wonder of the world” with great economic and social impact. It will mark a turning point for the city by offering greater mobility. With the growing city and the technology of space elevator there will be more opportunities for people to make living on Mars. A certain profile of people on Earth will choose Mars as their new home. These may include entrepreneurs who will prefer the opportunities of Mars over the saturated markets of Earth, or family people who will prefer to raise their children on Mars as a then more viable alternative than on Earth. Even if a tiny minority on our home planet, they will be sufficient in numbers to drive growth of a large city on Mars.

As the costs of migrating to Mars lowers with technology advances, one such advancement being the space elevator, there will be a point in time when the number of people who are able and willing to self-fund their migration to Mars, possibly using bank loans, will surpass the residents that are funded by the governor and businesses operating on Mars.

The growing population will support the market and the opportunities for new businesses. The governor organization will use this period to open the service platform to many businesses. It will become easier for new businesses to start operations and to introduce new products and services. The residents will enjoy higher variety and quality with lower prices as time passes.

As in the previous period, the city will use a portion of its finances for the next milestone - building the first industrial factory in space.

2100: First industrial factory in space. Industrial phase

Building on the first space elevator, a network of space elevators will speed up and improve the logistics between the surface of Mars, its orbits, the asteroid belt and Earth. The city will have a clear advantage over Earth in building a large industrial complex in space. The city will build the first factory in around 2100 and gradually form an entire industrial zone. This complex will have lower cost for transportation and construction as compared to the competition on Earth. It will employ high levels of automation with operations in space premises performed by robots and remotely controlled from Mars surface.

The factory will have strong competitive advantages over the industrial sites on the Earth in producing certain products, supporting special technologies and developing certain economies. For example, it will have easier access to asteroid-mined resources, will be able to use technologies relying on zero-gravity or vacuum, will be less exposed to risks of pollution, etc.

The industrial factory in space will define the identity of the city for many decades. It will direct its economy by developing its specialization in exported goods and services. Equally importantly, it will support the growth of the population of the city to a size that becomes recognizable and significant in our civilization.

2150: Population of 1 million

After building its first industrial factory in space in around 2100, the city will maintain average yearly growth of 4-5% to reach a population of 1 million by around 2150.

The city will become fully developed and self-sustaining, but still a partner to Earth. The service platform will have a wealth of active businesses and new Mars-native businesses will appear. The city will continue to be an attractive location for businesses but will no longer be dependent on entrepreneurs from Earth as local businesses will now lead its growth.

By covering the lower level needs of the residents, the service platform will free room for higher aspects of life to develop in a natural way. The people will use their free time for socializing, for parenting, for hobbies, for culture, for business, etc.

All aspects of life will still be well connected to those on Earth. For example, with service providers of Internet on Mars that solve network latency, for example by mirroring content locally, residents on Mars will be able to enjoy the same TV shows, sports events, etc. that their friends from Earth enjoy.

Some aspects of life may, however, have diverging development on Mars. For example, with the high degree of automation and artificial intelligence of the service platform and the infrastructure, there may be no need for taxes for business activity (like VAT on Earth) and the economy on Mars may become far more fluid than that on Earth.

The city on Mars will become a unique extension to human civilization. It will participate in the “global” (now interplanetary) system but will build its own lifestyle and add to mankind’s diversity.

Service platform

The city growth and the development path we described are driven by the interaction of three groups - the governor, the businesses and the residents.

The governor organization provides businesses with a platform for services and the infrastructure to access consumers and suppliers. In return the businesses pay for using the platform and infrastructure. The governor will maintain the infrastructure to ensure the businesses and people can reliably exchange goods and services.

The governor organization regulates the services and provides city residents with secure services as well as housing. In return the residents pay for the housing they rent. The rent covers access to the services, other amenities and the capacity of the governor organization to ensure (through regulation) that the services are available and do not put lives at risk.

All needs of the residents are met by the services the businesses provide, for which the residents pay the businesses.

Minimum set of services

The primary purpose of the service platform is to meet the biological and physiological needs of the residents. The governor ensures the availability of a minimum set of services on the platform that provide enough supply for all residents. The governor regulates these services to ensure they are accessible, safe to consume and with guarantied availability.

In the beginning, the governor will contract the service providers for the minimum set of services. Later, as the city grows and becomes more attractive to new businesses, the governor will ensure there is sufficient supply for the minimum set of services only by running the service platform and will only rarely directly contract service providers.

The design of the city positions the service platform to be the medium for the interactions among the governor, residents and businesses to achieve the milestones and grow the city. The design is not bound to any specific implementation of the different services. Instead it is open to accommodating the innovation businesses can bring to solve the challenges of life on Mars.

We will only look at examples for possible implementations of the different services in the minimum set:

• Shelter - Basic protection from the harsh environment on Mars, from radiation and bad weather, will be provided by the infrastructure, part of the service platform. A cover made of rammed soil at least one meter thick will form a cave that will provide sufficient space for living and protection from the natural environment on Mars. The cover will block the radiation from the Sun and Space. The cave will be intentionally larger than the room needed for the residents and will maintain better environment in terms of temperature and air pressure although not enough for living without additional protection. The infrastructure of the service platform will include inflatable habitat as a second level of protection. The habitat will maintain fresh air and constant room temperature. For the cases of emergencies, the infrastructure will also offer light protective suits and emergency spaces to hide. These three levels of protection will be constantly monitored and maintained in an automated way. The shelter will have an in-built communication system that will ensure connection to the control center and the rest of the world. We will look in more detail into this infrastructure in the next section.

• Air - Breathable air will be constantly recycled from imported and locally produced gases. Service providers will use a variety of technologies to produce and recycle air and will be able to choose the appropriate mix to optimize financial returns. For example, they can import oxygen from Earth, extract it from the water reserves of the city or recycle the used air. Regulations by the governor will include provisions for the quality of air, production capacities, redundancies and emergency procedures. Service providers will have the choice of specializing in supplying air or combining air supply with other services, such as air conditioning and heating.

• Water - Drinkable water will similarly be constantly recycled from imported and locally produced water reserves. Again, service providers will use a variety of technologies to produce and recycle water, optimizing their financial returns within the constraints of regulation and customer satisfaction. Since water is very heavy and costly to import from planet Earth, service providers will possibly use in-situ resources while the demand is small and may later supplement with asteroid mining if local extraction cannot keep up with the growth rate of the city. Service providers will have the choice of specializing in supplying water or combining water supply with other services such as those related to air and energy.

• Food - Residents require varied diet that may require a multitude of service providers. Possibly some service providers will specialize in imported dehydrated food while others will specialize in local fresh produce for example in automated vertical farms. Regulations by the governor will include provisions for the quality of food, capacity for production, import and reserve storage.

• Electricity and heating - Electricity and heating will be possible to produce from different energy sources - nuclear, solar, wind - and the city will have to maintain a resilient mix of those. Regulations by the governor will include provisions for the capacity and redundancy of supply.

• Waste management - Service providers that deal with waste management will possibly work with suppliers of food, water, air to optimize the recycling capabilities of the city.

Amenities

The secondary purpose of the service platform is to meet the higher-level needs of the residents. The governor will not necessarily enforce strict regulations on these since people’s lives do not directly depend on them, as the case with the minimum set of services is. Nevertheless, the governor may contract service providers for under-supplied services to maintain better lifestyle of the residents and overall attractiveness of the city.

Some examples of services that will use the same service platform are:

• Security - as the city grows there will be growing need for keeping the peace and resolving conflicts. Because the city will be equipped with highly monitored infrastructure that is since day one capable of and responsible for tracking people with the purpose of protecting them in case of emergencies, police and bodyguard services will be collaborating with the governor organization and the infrastructure.

• Health - similarly, the health of the residents will be a concern of the governor and there will be basic but well-integrated health monitoring capabilities in the infrastructure of the city. Additional services will be further supplied by independent service providers possibly with close collaboration with the infrastructure of the city. They can start with individual doctors and as the city grows build large hospitals.

• Education - the needs for education will rely on connection to Earth at least in the very beginning. Virtual classrooms, individual practices, coaches - these can all be done online even considering the latency between Mars and Earth. As the needs grow and local education facilities become viable, they will appear in the service platform. The city will be founded on exporting science related to Space research and it will be just a matter of time until education in more spheres of knowledge will be exported too.

• Entertainment - the need for entertainment and socializing will attract a variety of venues - cinemas, theaters, restaurants, cafes, pubs.

• And many more like sports, leisure, travel, shopping, etc.

All the services will be supported by the service platform and will in return support the city with amenities. The mix of services drawn by the evolving needs of the residents will shape the lifestyle of living in the Mars city and its unique culture.

Service platform features

The service platform will be instrumental to the development of the city and its design will need to stay focused on a few simple concepts that will allow it to evolve together with the city and at the same time stay reliable. These three concepts and their high-level design are:

• Modular infrastructure - The purpose of the infrastructure will be to connect service providers to service consumers. The entire city infrastructure will be composed of standardized modular building blocks that can transport goods from service providers to service consumers. They will also be easy to add, maintain and recycle. These modules will be connected and have common monitoring and control aided by artificial intelligence and robots. In the simplest implementations the individual modules will be controlled by a central control center but as the technology advances they will be autonomously performing basic procedures, too. We will look into the design of the infrastructure in the next section

• Regulation for services - Some services will be essential to life and other services will be highly valued by residents or businesses. For those critical services the governor will impose regulation so that the entire community can rely on their availability and quality. The regulation will be in the form of rules, service providers must comply to, and will be coded into the infrastructure, meaning that the monitoring and control capabilities of the infrastructure will extend to tracking the availability and quality of the critical services. The governor will have the power to enforce the regulation by blocking non-compliant service providers. The governor will also be monitoring the risks of future non-compliance and mitigate the risks by, for example, contracting additional service providers.

• Marketplace for services - The platform will be open to businesses to provide various services to the residents and to other businesses. The marketplace will be an open IT system serving as an interface between service providers and residents. It will provide a network of consumers and suppliers building on the automation, monitoring and control of the modular infrastructure. It will offer the possibility to make direct purchase transactions between consumers and producers but also build and run entire supply chains. It will also be open for extensions so that interested businesses can specialize in extending it with value-add services over the interactions on the marketplace.

The service platform will start small with the foundation of the city and will grow with it. It will also influence the three milestones of the development roadmap.

When the city is founded and enters its Science and tourism phase, the governor will be hiring the companies and staff who will accommodate the scientists and tourists. It will also hire service companies to provide the minimal set of services to support life in the city. As the economy in this phase is dependent on the capability of the governor to attract science and tourist projects, the number of operating services will be small, they will provide low variety of services and most of these services, if not all, will be considered essential so the governor will be contracting and regulating them.

Already at this point the governor will provide the common modular infrastructure to support delivery of the services. The governor will also regulate the services to ensure residents receive adequate life support and that relevant risks concerning service outages and people health are mitigated. The service platform will have developed two of its three key characteristics but will still be small and funded by the governor.

After the city passes the First space elevator milestone and enters its Real-estate phase the service platform will need to expand to support more than a thousand residents. It will add its third key characteristic - the marketplace for services. The platform will continue providing the common infrastructure and regulation over services and will now also be driven by competition based on the free market forces of supply and demand. At this point it will be common for more than one service company to provide the same or similar services, since they are now attracted by the market and not hired by the governor.

After the city passes the First industrial factory milestone and enters its Industrial phase the service platform will need to be prepared for hundreds of thousands of residents. The expanded economy will allow for high variety of services. The service platform will additionally boost variety and innovation by opening the marketplace and the underlying infrastructure to extensions by businesses. As a result, the overall level of uniformity of the infrastructure may get slightly reduced because some residents will be using extensions that others are not using, but as long as extensions do not compromise the compatibility of the basic functions of the infrastructure modules the businesses will be able to add a lot to the evolution of the infrastructure and increase the speed of development of the city.

Modular infrastructure

Finally, we will describe the modular infrastructure - the physical support of the service platform. It consists of rammed soil protective cover, connected modules for flooring and logistics, robotic drones for maintenance and control center for monitoring and control.

Cover

The entire city is covered with a structure made of bricks of rammed soil. The cover provides space for the residents to live in and a first-level protection from radiation and bad weather. There are also the second-level protection by the module inflatables and the third level protection by the emergency bunker we will describe later.

Experiments with Mars soil simulant suggest that the abundant soil of Mars may be used to create strong bricks with little additives if any at all. The weaker gravity of Mars will allow the structures made of rammed soil to be erected taller than equivalent structures made of rammed soil on Earth. This material will not require expenses for transportation from Earth allowing for large structures to be built at lower cost.

Our design will use honeycomb tiling structure with hexagons with diagonal of 4 meters, where every hexagon borders with exactly 3 columns. The columns will be 1 meter in diameter and 6 meters tall. The columns will support 60-degree roofs that top 12 meters above ground.

The cover will provide isolation in terms of air pressure and temperature. It will be possible to maintain constant air pressure in the range between 20% and 50% of that on Earth and temperature ranges above zero degree Celsius. Although this will not be enough for humans without extra protection it will allow for the modules inside the cover to be more light-weight and more flexible. It will also allow residents some freedom for short activities outside the modules.

The city will gradually build its cover to meet its population growth. The first phase of the development of the city will require cover for 1000 residents, which will be made of 3 neighborhoods, each being 180 meters in diameter and consisting of 6000 cells (for private, social and industrial use) arranged in honeycomb tiling in 45 rounds around a center cell. The city will use many such neighborhoods in clusters around points of interest on the surface of Mars. A total of 3000 such neighborhoods will be required for the city to reach population of 1 million. One neighborhood will look like this from the outside:

The habitat should be good from psychological point of view, too. Therefore, it should provide sufficient space and light. Artificial light sources will be attached to the bottom side of the cover to substitute sunlight. The structure will allow for a range of sight of a few hundred meters. Colored sculptures will imitate trees in the distance. One neighborhood will look like this from the inside of the deployed habitat modules we will describe later:

Drones

The cover is constructed and maintained by robotic drones. The drones also lay the modules inside the cover. These drones will be designed to be simple and cheap. They will be controlled centrally by the control center and will be most effective when swarming in large numbers over a task.

A single drone is configured to perform one or more of the following tasks:

• Collect soil - The drone will be able to dig into the Mars surface, extract small chunks of soil and store them in an in-built container. The drone will operate like an ant, rather than like a bulldozer, meaning that it will be equipped with small rippers - claw-like devices - and will be able to dig soil in small chunks to collect a desired amount of soil rather than collect a large quantity of soil at once

• Ram soil into a brick - The drone will be then able to press the collected soil in its in-built container into a brick. It will be equipped with the mechanism needed to mix the soil with necessary additives and exercise the necessary pressure.

• Move a brick of rammed soil - The drone will be able to move a brick - either a brick it produced or a brick it collected - to the destination pointed by the control center. It will be equipped with communication device to connect to the control center. It will also be equipped with six or eight legs to be able to move itself (together with the brick it carries) on the surface of Mars as well as climb on lain bricks. When it needs to climb on top of a tall structure, for example to lay a new brick or to collect a previously lain brick, it will swarm with other drones to first build a ramp of bricks to make path to the target position.

• Move a module (together with other drones) - The drone will be able to also move larger objects - obstacles, debris, other drones, and very importantly the modules we will describe later. Because those objects may be larger than a single drone, the control center will co-ordinate a few drones to work together and move the object as a group.

In addition, the drone will be able to perform supporting tasks, such as going to a re-charging or a cleaning station.

The following sequence shows a simulation of drones swarming to build the cover structure:

We see in the sequence how a few drones will prepare bricks, others will simultaneously build a ramp, while others will lay out the column. The drones will keep producing more bricks and constructing the ramp and the column similarly to how a 3D printer creates a print layer by layer. Once the cover is complete then a few drones will reclaim the bricks from the ramp for reuse in a next section of the cover.

The design of the drones implies that by working in groups and consuming more time to build and maintain things they will compensate the fact that they are not individually strong. If we consider the cover structure as described and scaled to support 1000 residents, which will be enough for the entire first phase, it will require 90 million bricks. We will assume 1000 drones, one per resident, and average time to build a single brick of 10 minutes and average time to move and lay a single brick of 10 minutes. The time required to build the cover structure will be 3.5 years. Since the first phase is projected to 20 years, until 2050, it will be possible to build the cover with these 1000 drones, leaving sufficient time for dealing with malfunctions, time for recharging and other tasks.

Modules

Within the cave of the cover, the city will be built on top of a layer of connected modules. The modules will be lain on the ground arranged in a layout that completely covers the surface around the columns of the cover. These modules will be the flooring of all areas in the city - private, social and industrial. The modules will be standardized and therefore they will be possible to be reused, repurposed or replaced as needed.

The modules and their accompanying maintenance drones will be produced on Earth and need to be transported to Mars. We assumed a weight of 1500 kg for a set of one module and one drone in the calculations presented in the previous sections.

The basic module is a hollow hexagonal prism of 2 meters in length for a side and 1 meter in height when deflated and 4 meters in height when inflated.

The module has three layers:

• The lower layer is for the logistics in the city - for transportation. It contains 3 tubes connecting its opposite sides with an electro-mechanical dispatcher unit that controls the movement of capsules in the tubes. The dispatcher unit will maintain the speed of the capsules in transit through the module, will pull the capsules that are sent to this module out of the transport tubes and will store them in the middle layer, and will put the capsules that are sent from this module into the transport tubes.
• The middle layer serves as a storage for resources and as a highly protected environment. The capsules that are stored in the middle layer of the module can be used by appliances placed in the upper layer of the module or can be just stored for future use.
• The upper layer is an inflatable cover that provides the living spaces of the city. When inflated it is 3 meters high with a volume of 30 cubic meters. The top plate is supported by six inflated columns. These support columns can be attached to the neighboring modules. Any of the six sides can be covered to form a wall between the modules or can otherwise be used as a door to the next module. When the module is deflated, the inflatable supporting columns and the wall covers get inside pockets in the middle layer while the top plate lays securely on top of the middle layer.

The most visible part of the module is the inflatable upper layer. This is where people live and work. The same standardized structure of the module will be used for all needs - private, social and industrial areas - so that they can interconnect and work together as the transport backbone of the city. The modules can be equipped with different instruments and will store capsules with different resources to fit the purpose of the area they are located in. For example, modules in private areas will have home furniture and appliances, while industrial areas will have office furniture, manufacturing machinery or may be even deflated if used for robotic activities.

The middle layer of the module is usually used for storage. But in private areas, its highly protected environment is also used by residents as a healthy place to sleep in and as an emergency bunker. This layer can be equipped with instruments for health monitoring and treatment.

The module is always participating in the logistics system of the city as a transport relay. It is the lower layer of the module that is responsible for that. The module is connected to other modules tiling in a honeycomb structure. The tubes of adjacent modules get connected to form long pipes for transportation of goods in the capsules.

This example city plan shows the modules of a section of a neighborhood with the private areas of residences in yellow; the social areas of gathering places in blue, streets in white and parks in green; the commercial areas of shops, offices in red; and the industrial areas of factories and labs in gray. The lower layer of the modules connects all spaces in a continuous logistics system:

Control

All infrastructure components are controlled centrally, heavily aided by IT systems and artificial intelligence. The control center manages the transactions in the service platform, optimizes the path for deliveries, mitigates risks of failures, navigates the drones to build new housings and repair existing housings, conditions living spaces and assists the residents.

The control center also serves as the main interface in communication between the residents, the businesses, the governor, the service platform. For example, when a resident wants to report an incident they will first talk to the AI.

An important role of the control center is managing the logistics of the city. All essential goods and resources travel through the city inside the transport tubes of the lower layer of the infrastructure modules. Standardized reusable capsules are used to contain the resources. The capsules can contain and transport one resource at a time. A basic container can be used to store resources that do not require special handling, such as water, food, waste, but specialized units with the same capsule shape can be used in the transport tubes to transport and store other resources. For example, a battery capsule can store and transport energy for electricity; or high-pressure tanks can store and transport oxygen or air.

Businesses, in their role of service providers, will fill in capsules with the goods they supply and put them into the transportation system. Residents and other businesses, in their role of consumers, will receive the capsules, store them locally, consume the goods and eventually return the capsules. The control center will manage the transactions and will navigate the capsules from supplier to consumer.

The infrastructure for 1000 residents - with 3 neighborhoods each consisting of 6000 cells - will have a total capacity of 622,080 cubic meters of deliveries per day, assuming 50 cells as average distance between supplier and consumer, capsule volume of 0.02 cubic meters, a limit of one capsule at a time in a cell and average velocity of a capsule of 4 m/s. Additionally, assuming a total of 6 cubic meters of supplies necessary for the basic needs of one person (air, water, food, energy, waste), then 1% of the capacity of the transport system of the infrastructure will be required for life support leaving a lot of room for mitigation of risks of local malfunctions, congestions and other possible disruptions. The remaining 99% of the capacity is available for additional commercial use on the marketplace of the service platform.

Finally, the control center is responsible for city’s urban planning. All components of the infrastructure are managed by the control center and work together to move entire neighborhoods from locations of declining attractiveness to locations with better potential. The city will be able to get closer to newly discovered deposits of natural resources, move away from locations near depleted resources or where disasters stroke, or simply move quarters around points of interest where people prefer to live.

This sequence of diagrams, illustrating the move of a block that is close to an area with pollution (marked with a biohazard symbol) to a site of a new resource (marked with a green leaf symbol), demonstrates the power and flexibility of the infrastructure in the evolution of the city.

References

• https://SpaceColonyOne.github.io/MarsCityState/ - Web location of this document
• https://github.com/SpaceColonyOne/MarsCityState - Source of this document
• https://ourworldindata.org/world-population-growth - Data on world’s population growth
• https://www.researchgate.net/publication/222382174_Population_Growth_in_the_World’s_Largest_Cities - Data on expected population growth for cities
• https://en.wikipedia.org/wiki/Moore%27s_law - Information on Moore’s law and empirical data on exponential growth of technology advancement
• https://en.wikipedia.org/wiki/Asteroid_mining - Information on asteroid mining and distance from Mars to the asteroid belt
• https://en.wikipedia.org/wiki/Three-sector_model - Description of the three-sector model in economics
• https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20040075697.pdf - Comparison between the working cost estimating methodologies of the cost engineering functions in NASA Marshall Space Flight Center (MSFC) and ESA European Space Research and Technology Centre (ESTEC)
• https://en.wikipedia.org/wiki/Space_elevator - Information on the technology of space elevators
• https://en.wikipedia.org/wiki/Earth_structure - Information on the technology of rammed soil bricks
• https://www.theverge.com/2017/4/27/15436154/mars-soil-simulant-study-building-human-missions - Research on use of Mars soil for bricks