If humans are destined to visit and eventually colonize Mars, they’ll need somewhere to live. But building structures in space isn’t without its challenges.
One major obstacle is transporting construction materials to the Red Planet. Engineers have been hard at work on transforming planetary resources into building supplies for space habitats.
Inflatable Space Habitats
As humans move into the era of extended space travel and colonization, engineers are designing different materials and shapes for habitats that will let us safely live for long periods of time in the harsh environments of space. One promising material is an innovative polymer, which is both strong and flexible. The material is called MAdFlex, and it can be used in a sandwich configuration that allows a dome to flex but not collapse. It is possible to achieve this by selecting the right materials for each of the two sandwich faces. Researchers at Embry-Riddle Aeronautical University are developing strain sensors that can be used to monitor the structural behavior of this new material and to detect any damage or deformation.
A big advantage of this type of material is its flexibility, but it also offers other benefits. It is very lightweight, which will cut down on the amount of fuel needed to launch a payload into space. It is also foldable, which makes it easier to fit into a rocket’s cargo bay.
Another advantage of the MAdFlex is that it is highly resistant to micrometeorites and other debris floating around in space. This is particularly important, because the International Space Station is showing signs of wear and tear after 20 years in low Earth orbit. The next generation of space stations will need to be even more durable than the ISS.
Earthy Materials
If humans are ever to travel to Mars or other distant planets, they’ll need somewhere to live. But hauling tons of construction materials across 225 million kilometers of space isn’t feasible—or affordable.
Researchers are looking at ways to use Earth’s natural resources as building materials for future space habitats. One idea is a doughnut-shaped rotating space station that would produce 0.9-1 g of artificial gravity through centrifugal force. Another approach is a system that would make use of the thermal properties of Earth’s water ice. This material is not only highly insulating but also has low thermal conductivity.
Other potential building materials include metals such as aluminum and titanium, glass, and polymers. Transparent aluminum is a particularly attractive choice because it’s resistant to radiation, which could be a big concern for astronauts on a long mission.
Another material with potential is graphene. This allotrope of carbon is incredibly strong, with 200 times the strength of steel, yet much lighter. It could be used to reinforce a structure and strengthen the materials that make up the outer layer of a space habitat.
Modular Space Habitats
After 20 years in orbit, the International Space Station is starting to show some wear and tear. In the last year alone, a toilet and an oven have stopped working, and cracks in an old module are leaking air. So with NASA and private companies aiming for deep space exploration, the next generation of habitats needs to be modular and flexible to accommodate a range of mission requirements.
One of the newest options is an inflatable modular space station, designed by Sierra Nevada Corporation. Called the LIFE Habitat, it’s made from a Kevlar-like fabric and can fold down to fit the payload size limits of most rockets. The structure is three stories tall when fully inflated, with enough room for four astronauts and their equipment.
Other designers have taken a different approach to the problem of building in space. They’ve used the same expandable fabric that makes up the International Space Station, but in a new design. The Aurelia Institute’s TESSERAE module is built of flat-packed modules that will autonomously self-assemble in space, and each module includes electro-permanent magnets to control the bonding process.
To assess the performance of these habitats, researchers have simulated low-speed impact dynamic responses using FE simulation software. They’ve also evaluated their ability to withstand external regolith shielding and internal pressure while minimizing structural mass.
Sustainable Space Habitats
Long-term space habitation requires more than just the capability to support astronauts; it needs to be self-sustaining. This means creating an artificial ecosystem that can provide food, water, and oxygen while minimizing the risk of harmful microbes and radiation exposure. It also requires closed-loop technologies that can recycle and reuse resources, especially those shipped from Earth.
To meet these requirements, scientists are exploring several different types of sustainable space habitats. One type is the expandable habitat, which uses materials that can expand to create room for astronauts. These structures can be built on the Moon or Mars, and they’re an important step toward achieving planetary settlements.
Another option is a fully automated, self-sustainable space habitat. These structures would use plants to produce food, water, and oxygen while recycling waste products into new building materials. This technology would eliminate the need for expensive cargo missions from Earth.
Inflatable space habitats are another option for sustainable space habitation. These structures would be designed with concentric cylinders, and they’d be constructed from materials that can withstand the pressure of the outer shell. The walls of these structures would be covered with regolith, which is a loose layer of surface material that covers solid rock on the Moon and asteroids. This material would protect the structure from meteoroid debris and radiation while enhancing stability.