Unmanned setup of a whole settlement

Remote controlled machinery does construction work

The unmanned setup of a whole settlement is a safe and economical way to colonize the planet Mars. There are many uncertainties with the alien environment. The equipment is tested on Earth thoroughly, but still the influence of the Martian environment might not be understood completely. The safest way is an unmanned setup by automated and remote controlled machinery. This should not forbid some human presence on Mars while the settlement is being prepared. A limited human presence would make trouble shooting infinitely smoother and faster. These early workers would bring their own food and use artificial life support while they helped to prepare the full settlement.

Initial exploration

Data for the best location of the settlement must be gathered, including radiation protection opportunities, water and mineral resources and general geological exploration. Depending on the amount of funds available and the efficiency of robotic exploration it might be better to precede the settlement preparation with some human exploration, in particular for geological exploration and data gathering and the supply of a mineralogical lab to the Martian surface. This would include some initial industrial capacity for the preparation of in situ fuel, for a dramatic reduction in costs. This would be a base, and not a settlement.

Transportation to Mars

After evaluation of all known data the location for the initial settlement is determined. The equipment is brought to the Martian surface. This will take several space flights. The equipment for energy production is brought first, then construction and materials handling equipment.

Cargo landings on Mars with large aeroshells such as the SpaceX Starship, with precise landing points, would be ideal. The feasibility of a space elevator for landing large amounts of cargo should be analyzed with respect to the costs, as well as options mentioned in Landing on Mars. However, with the planned capacity of 100+ tonnes per SpaceX Starship, little else is required.

Construction

Houses, energy-generating equipment and greenhouses are setup and brought into function, using local AI controls and some remote controls from Earth. This habitat must be large enough to provide working space and food production space for an initial population. This could be done with the following concepts:

• Natural cave/lava tube
• Artificial cave
• Inflatable habitat
• Sintered regolith habitat
• Buried rigid habitats

The remote control from Earth of industrial activity including the construction of buildings on Mars presents some special problems. The artificial intelligence acting on instructions with up to 44 minutes round trip communications delay would need to know what to do in many cases. For example, the concrete that it mixes must never be left to set in the mixer while waiting for instructions to deal with an unexpected circumstance. Various industrial operations cannot be stopped without harm, so the operations will need to be simulated and tested on Earth to ensure that they run smoothly. The AI will need to have fail-safe options or the required autonomy to deal with failures and modify the construction plan if required. This would be much simpler with some limited human presence.

Greenhouse field trial

From the experiences of Biosphere 2 we cannot assume a fully passive stability of the ecosystem. The material of the walls might react with the artificial atmosphere and the substances of the soil, causing a shift in concentration. Also, the hermetic sealing is probably not perfect. Conclusion: Machinery for automatic control of water, air and soil chemistry as well as pressure control is needed.

A trial greenhouse system with ample monitoring is required. First the greenhouse is built and an appropriate air pressure is created. The floor of the greenhouse is covered with powdered regolith, possibly treated to remove perchlorates. This regolith is enriched with fertilizer and moistened with water. Terrestrial soil implants microbes are added to create soils from the regolith. Some aerating material, such as vermiculite, is required to provide air circulation in the soil. Seeds of pioneer plants are brought in to start the biological cycle. If applicable, the greenhouse is artificially lit and heated.

Greenhouses are not forests, or in any way complete biomes. They are artificial biological systems designed to create food and treat atmosphere. A true artificial biome, capable of supporting a significant population while maintaining a complete biome would be gigantic. However, a small working test biome should be a required proof of concept before allowing human occupation. The trial should prove the stability of the biosphere with the metabolism of living plants, decomposition of foliage and reproduction. Some small animals, such as chickens and rabbits could be brought to Mars and added to the biome.

In parallel, automated food producing greenhouses should be tested and put in operation before the arrival of the settlers.

Using hydroponics

An alternative to soil preparation would be hydroponics. The development time would be much shorter. There is increased complexity in troughs for holding the soil and pumps for distributing water and nutrients on a regular schedule, but the soil itself only needs to provide mechanical support for the plant roots, adequate drainage properties and a lack of chemically toxic substances. The greenhouse would be robotically harvested, feed automatically given to the animals and fish (if any), and their wastes automatically recycled.

This would be a large task both in technical complexity and in size of the initial capital investment, but likely cheaper than an actual complete biome.

Biological reactors might be included in the arrangement, to add nutrients to the feed water, create the growing substrate, and handle waste conversion into new soil or plant food.

Arrival of the settlers

The human settlers would move to Mars after completion of all construction and evaluation of the tests. Ample food provision should be sent as well, as a backup in the event of failures in the greenhouse systems. The humans would progressively be integrated into the life support system, and services transferred from artificial life support to natural life support.

Regolith transformation into soil

In the presence of sufficient food and energy with well chosen species, conversion of regolith to soil should be fairly rapid. An example of this on Earth is the return of life to the blast zone of Mount St-Helens. The zone returned to a significant vegetation cover within a decade. Careful soil husbandry should reduce the time significantly.