Our homes are the places that define us; those warm private spaces that we depend on for work, respite, and haven from the harsh realities of the wider world. On Earth, the buildings and dwellings humans spend the majority of their lives in serve as reflections of our society’s culture, beliefs, and values. So if the shelters we make for ourselves truly mirror and influence our everyday lives, how might that sentiment be translated to living in space?

The kinds of structures future explorers might live in on other planets may be more critical to space exploration than sci-fi depictions of cities and homes in a galaxy far, far away suggest. As NASA’s desire for long-term human space colonization comes to fruition with planned crewed missions to Mars, establishing safe and well-made human settlements for life off-Earth is one of the agency’s most urgent tasks.

Putting down roots on Mars is an extremely ambitious goal to accomplish this century — but the reason why isn’t to do with rockets, necessarily. Rather, it is because any human settlement on the Red Planet will have to fight tooth and nail to experience even a modicum of ecological success.

One of the most accurate parts of the 2015 movie The Martian is that when Matt Damon ends up stranded on Mars, everything about the planet is trying to kill him, and his habitat holding up is his only hope of survival. Human dwellings on Earth have evolved to thrive by taking advantage of the surrounding environment, but astronauts on Mars have no such advantages.

Instead, like Mark Watney, they will have to deal with various ill-fated conditions for life, including a complete lack of natural resources, harsh weather including dust storms and freezing temperatures, low gravity, and high levels of dangerous deep-space radiation.

Yet some sci-fi classics like Star Wars also offer alternative, less bleak visions of humanity’s future off-Earth. Can any of these fantasies become reality? It might be more possible than you think.

Cosmic Utopia

If the history of humanity has taught us anything, it is that we are motivated by the idea of founding our own Eden — whether on a new continent or merely a new town. A similar philosophy drives one of the most popular science fiction tropes ever: Humans going out to create a thriving utopia in space. Scientists and sci-fi authors alike have devoted years of their lives to imagining what innovative space settlements could look like, from spacecraft that resemble the donut-like Torus designs pioneered by German-American aerospace engineer Werner Von Braun, (which could soon be the working model for future space hotels), to the more well-known interstellar Bernal Sphere, first proposed in 1929 by Irish physicist John Desmond Berna.

Like Von Braun’s concept, many early space habitat designs started as idealized versions of space stations or lunar bases. One of the most serious efforts was the 1959 U.S. Army study Project Horizon. The army’s plan involved building a military facility that would be buried under lunar regolith in a bid to protect humans from radiation, freezing temperatures, and micrometeoroid and space debris impacts. The idea was eventually nixed when NASA’s Apollo missions in the 60s and 70s revealed how tough lunar soil is and how difficult it would be to burrow into it.

In 1989, Gary Kitmacher, former architectural manager for man-systems on the International Space Station, took a shot at an alternative: He designed an inflatable habitat that could accommodate the needs of about a dozen astronauts living on the surface of the Moon. The sleek, dome-like structure included a bevy of different mission-related and personal rooms, such as a fully-equipped science lab, exercise rooms, hydroponic gardens, and private crew quarters.

Of course, neither project came to be, but these and several other fledgling space habitat projects have gone on to inspire similar present-day concepts that have evolved in scale, creativity, and feasibility. In fact, one particular Mars habitat concept started out as an alternative module for the ISS.

In the late 1990s, American architect Constance Adams worked with NASA to design TransHab, a large-scale inflatable spacecraft that would have increased the crew’s living space. While there are many advantages to using lightweight inflatable habitats, Adams once noted that before her creation, the biggest challenges facing space inflatable tech were strength, safety, and their need for a firm structure to maintain the form. With a soft inflatable shell, hard inner structural core, and three roomy levels, TransHab was the first hybrid structure that could be used for a pre-deployable Mars habitat. Although NASA did create a prototype, the project never received the funding it needed to get off the ground.

Space agencies need off-world homes to be pleasant for astronauts to live in. There are at least five aspects that every successful human habitat for long-term space exploration must have, Manoranjan Majji, an associate professor at Texas A&M University who studies aerospace robotics, tells Inverse:

• A protective radiation-proof shell
• Artificial gravity
• Sustainable food and water
• Robotic systems, including the ability to manufacture bots
• The ability to grow

“Protection against extreme environments is very important,” Majji says. “Almost every part of engineering needs to contribute to that.” If you manage to overcome the cosmic ray problem, then astronauts will need artificial gravity and sustainable food and water to survive. Ultimately, Majji says, a combination of robotic systems and tools like 3D-printing will make these architectural obstacles easier for future explorers to overcome.

Future settlements will also need to be capable of growth and even generate some commercial value while manufacturing and demonstrating these future technologies. This will be as true for building astronaut labs and quarters as it is for creating scenic regions and hotels for space tourists.

Combined, these needs show why having a diversity of space habitat design concepts is so vital, Majji says. “If we have flexibility in terms of the architectural elements,” he explains, “we will have a lot more freedom in terms of what we can efficiently realize.”

But what kinds of freedoms will the space habitats of the future offer us?

Flashing Forward

Ferrying resources from Earth to other planets takes a massive amount of time and energy, but these costs could be mitigated by using materials grown in space to build the next generation of multi-planetary structures. One concept, called myco-architecture is being tested at NASA’s Ames Research Center in California. The project imagines astronauts living in structures made out of fungi. Mycelia can create precise, complex threads and is easily scaled up. The organisms can also be coaxed into making leather-like materials as well as large-scale, durable habitats. Scientists could one day create other forms of biomaterials, medicine, and even food needed to sustain astronauts for the duration of their missions using similar bioengineering techniques.

In fact, most habitat designs, including one that would rely on the power of fungi, seem to favor a circular resource economy, one where nearly everything is recycled and used to power other systems or needs. Hopefully, such advances could offer explorers a greater variety of produce and materials than what fictional astronaut Mark Watney had to in The Martian.

And as humanity moves ever-closer to becoming a space-faring species, other nations are ramping up efforts in space architecture design. In 2017, the United Arab Emirates announced that they would aim to colonize Mars within the next 100 years, putting a rush on Dubai’s Mars Science City, a project whose goal is to create the first stable human settlement among the stars. Using a combination of 3D printing and sand, the concept imagines a sea of interconnected domes that will stretch across more than 176,000 square meters of Emirati desert — a project that could span the length of about 30 football fields. The city hopes to be fully operational by 2024.

“Most architectural models that I’ve seen use Martian rock materials to build modular spaces that blend in with the natural landscape,” Paul Weiner, a Denver-based contemporary artist whose hobbies include conceptualizing Martian aesthetics, tells Inverse. He agrees with the theory that local martian materials (like sand) might be combined with 3D printed ones to create durable habitats, and says even interior design might “similarly be optimized for robotic printing.” NASA too is also deeply invested in using 3D-printing technologies as a promising method to create sustainable deep space habitats, as they’ve held multiple competitions to energize and educate the public on the topic.

Still, keeping humans happy and healthy during a long-duration space mission is more challenging than it sounds. On a years-long trip heading towards an environment far removed from everything humans are familiar with, every aspect of their refuge has to be carefully cultivated. Architect Chris Lawson, whose U.K.-based architectural firm has envisioned several kinds of futuristic habitats, tells Inverse that when designing these places, he often thinks about how to create spaces that combat isolation and feelings of reclusiveness. One way he likes to do this is find ways to create green areas, or places that remind people of nature.

“We all get lonely, and you try and imagine how loneliness feels that far away, that unconnected in a hostile environment,” Lawson says. “It’s going to be a long, long time until you’ve got cities [on] Mars.”

Although current astronauts have only been sent on relatively short trips to space, the ISS has served as an important test bed in investigating what kinds of structures might allow astronauts to accomplish their missions in comfort. Some of these tricks include ensuring that the interiors of these spaces do as much from the inside as these structures do from the outside. Aboard the ISS, NASA for example, uses LED lighting to keep crew members from feeling depressed and to regulate their circadian rhythms, which promotes good sleeping habits. We’re still decades away from having to prepare travel accommodations on Mars, but at least for some, helping to bring to life concepts people have previously only dreamed of is as exciting as it is alien.

“There’s a moment of emotion when presenting something that’s not been thought [of] or conceived by a client,” Lawson says. “When we’re able to show things that they’re not able to imagine, that spark joy and emotion, it’s something beyond words.”