In 1991 eight people in Arizona entered a strange contraption: a 3.14-acre glass house called Biosphere 2. They would stay for two years in the enclosed facility in the Sonoran Desert, which was home to five different ecosystems. The goal was to study how people and ecosystems survived in the sequestered, self-supporting habitat and to demonstrate the viability of a similar setup for future space travel.

It was an early “analog astronaut” experiment: a study that asks people on this planet to pretend to be spacefarers. The idea has always intrigued me. I love a “Can I actually do it? How will I react?” challenge. Usually for me that involves tackling some pointless, agonizingly long trail-running trial. The idea of applying my efforts to space research rather than individual satisfaction was appealing.

A lot of people must feel similarly because today the globe is dotted with such analog facilities. For weeks or months, small crews get locked inside a habitat, capsule or settlement to simulate a space mission. They venture outside only in a spacesuit, if at all, and interact with no one but their crewmates. Researchers study the systems that sustain the facilities, the procedures and instruments the participants use, and their psychology and biology—the scientific versions of “Can they do it? How will they react?”

Last month I gathered with those who’ve participated in such experiments at Biosphere 2, which today is operated by the University of Arizona. Located northwest of Tucson, Ariz., it hasn’t been used for its original, sealed, astronautic purpose since 1994. Today it is used for research related to climate change, biodiversity and sustainability. The occasion for this particular four-day meetup was the Analog Astronaut Conference, an annual gathering to share results, plans and experiences in simulated space research. Participants were united in their desire to advance space travel while remaining stuck on Earth and to make Earth more functional in the meantime.

At the opening reception, I felt separate from my cohort and doubtful of the enterprise. The group felt very grouplike, and the mood was idealistic—as in “We are a family whose earthly explorations will enable a better and inevitable future in space.” Rightly or wrongly, I don’t tend to be a joiner, and I’m skeptical of human space exploration’s scientific value and long-term likelihood. Cynic, realist, whatever: when I stood around chatting with my free drink, surrounded by optimism, I harbored some reservations about the usefulness of analog astronautics and the motivations of the participants.

Magnificent Desolation

Biosphere 2—Earth being Biosphere 1, the original—was never a secret. The project was launched with a high-profile publicity campaign. But the site feels slightly less removed from society than an exercise in living on a distant planet or isolated spacecraft should. On the small highway leading toward the facility, a big green sign like one you’d see at an interstate exit points the way. Along the smaller road in, ads encourage drivers to purchase custom home sites—right there, with Biosphere 2 as their new neighbor.

The land around Biosphere 2 could be described the same way Buzz Aldrin talked about the moon: “magnificent desolation.” Cacti spike the ground, and behind the facility, the Santa Catalina mountains rise, rocky and Martian-like, more than 9,000 feet into the air. That geography is part of why the actual Biosphere 2 building looks so striking: Two ziggurats made of tessellated glass triangles are connected by a long, glass rectangular structure. Jutting perpendicular from the structure are greenhouse-shaped domes, in front of which is a Taj Mahal–like entryway. Behind that is a white bubble that resembles an indoor tennis court. It looks like it does, in fact, belong on another planet.

Inside are miniature ecosystems—ocean, mangrove wetlands, tropical rainforest, savanna grassland and fog desert. Trees reach toward visitors, and water shimmers just beyond reach. On my first night I decide to take a walk around inside before the conference starts. It feels simultaneously like being in a very large municipal botanical garden and a small-town aquarium.

More than 30 years ago, this setup didn’t quite work for the Biospherians: they couldn’t get enough calories or oxygen from what the structure had to offer. Bacteria in the soil sucked up the air and produced carbon dioxide, leaving the participants with oxygen levels similar to those at the top of a 14,000-foot peak—what people in my home state of Colorado call “a fourteener” and love to post pictures of themselves summiting. In the Biosphere, people struggled to climb stairs and to stay asleep without apnea waking them up. Crop failures led to food shortages, which led to hangriness and weight loss. Ants and roaches got into the supposedly sealed habitat. The facility got oxygen injections, and the team had some food supplies stored ahead of time—cheating in the view of some, but who wants to die in a glass house? Mostly, in the public eye, Biosphere 2 is considered a failure, and its experimentation is seen as only pseudoscientific.

But Phil Hawes—its chief architect, whose keynote opens our Analog Astronaut Conference—doesn’t agree. “That’s not anybody who understands what a scientific experiment is about,” he says of the naysayers. The results surprised the team, which meant its members were learning, which is what science is about, he adds.

Listening to Hawes, I feel the corners of my mouth draw down. Sure, they learned some things. But the whole project seemed to be set up more like theater than like science. And the many millions of dollars it cost could likely have netted more and better ecological or space research—not that scientific funding is a zero-sum game—if they were spent on something other than a very specific manifestation of the back-to-the-land movement.

Yet the gathered analog astronaut community—whose members may, for all I know, have their own biospheric doubts—is here now to continue the journey, hopefully in a more rigorous way. And while the rigor of research conducted in modern analogs varies, plenty of peer-reviewed papers attest to the results and significance of the experiments.

Dressed in flight suits and swag patches from various analog missions, the group is generally onboard with the motivating mission Hawes describes: “advancing this strange sort of human desire to have an adventure.” The individual part of that desire, it seems to me, weighs as heavily as a motivating factor as the scientific outcomes do, but that’s the part I identify with most.

Dreaming of Escape

Being at Biosphere 2 for the conference itself feels like an adventure—and kind of like an analog mission in its own way, which is what tells me that maybe I’m not actually suited to this particular type of adventure. I constantly feel lost and like I’m breaking the rules. I prefer feeling competent and in control, and I hate to feel like I’m in trouble, so at Biosphere 2, a constant low-level anxiety simmers in my bloodstream.

Though you can’t really get lost in the tiny, simulated space settlement that most analogs use, there are strict procedures and schedules to follow all the time, and overlords make sure you are following them. At the biosphere, I wonder which section of glassed-in trees I need to go through to get to the talk about how cave diving is like living on the moon. Is it okay that I’m walking in the opposite direction of the arrows painted on the ground? Will an authority figure yell at me if I accidentally open a door that was meant to remain closed?

Mealtime, held on the patio overlooking the facility, is also an adventure. All food is vegetarian—as that on long-duration, long-distance spaceflights would also likely be—and I watch as people consistently load up on the more stomach-sticking and flavorful elements: shredded cheese, salad dressing, pools of hot sauce, dessert, dessert, dessert.

The conference-goers are housed in casitas above the biosphere (no, we don’t get to sleep next to the fake ocean where two researchers unaffiliated with the meeting are currently trying out an underwater bubble house). In the casitas, we share rooms or common spaces, so I have to greet strangers before I’ve had coffee, just like in college—or on a space mission.

But the most missionlike thing about the conference is that when it’s no longer tourism-business hours, the gates on the road out front close. If you leave the Biosphere 2 property, you have to drive a car so the gate will automatically open. And to get back in later, you must call to ask permission. My movements feel restricted; my choices feel limited; my personal space feels small; and my everything feels surveilled. If I think about it too much, it feels like the Biosphere 2 ants are marching softly around my skin.

One night, to feel a little free, I go for a run down the road to the highway. When I hit the closed gate, I slip illegally through a gap between the metal and the fence post, glancing behind me the whole way as if the Biosphere Police, who don’t exist, will chase me. When I slip back through the gates upon my return, I look toward the horizon for their imagined flashing lights.

I can already tell that if I were locked in for a true analog mission (let alone the real deal on Mars), I couldn’t hack it. “Bolt,” my brain would whisper to me, until I escaped to die alone. At least, though, I would have lived free.

A Group Song

On a small piece of the Biosphere 2 campus, University of Arizona scientists have reinvigorated an old part of the original complex—the initial building that housed a Biosphere 2 prototype. Neglected for years, it required modern researchers to dig inches-high dirt and mouse poop out before they could turn it into SAM: the Space Analog for the Moon and Mars. One night of the conference, researchers give us a tour.

It looks like a large RV that belongs to a small cult. In the living quarters, mattresses lie head to toe on the floor against metal walls. A rack of Tupperware containing dry goods looms above the kitchen. Farther back—after we crawl through a tunnel—is a room glowing purplish from grow lights that shine on a little stable of plants.

Here we’re instructed to take off our shoes and descend a ladder so we can see SAM’s “lung”: a room-size weight suspended over an underground cavern. As the pressure inside SAM shifts throughout the day, the weight rises and falls with the expanding and contracting volume of air, keeping the pressure consistent.

It feels like it could collapse at any moment, though it can’t. People chatter and take pictures and nudge the weight. And then someone asks if one of the University of Arizona team members will sing a song, a thing this scientist has apparently done previously for visitors. I cringe inside—this seems like one of those too-earnest “group” things that make me nervous.

Then the scientist smiles coyly, and soon his voice resonates in the lung’s cavity. Everyone goes solemn and quiet, having an isolated experience together. I feel my inner cringe soften and let myself think about how it’s nice, actually, to be underground in a lung with people who I may never see again but will always remember as being in this lung, listening to this song come from someone else’s lungs. I understand that this sensation is probably what motivates the analog astronauts: a sense of community centered around new and strange experiences. I get that—I even get feeling a little idealistic about it.

And while that doesn’t translate to dropping my space skepticism, it does make me think that it’s okay if a good deal of what comes out of astronaut analogs is about and for the astronauts themselves: the adventure of disappearing from their regular life to do something strange with strangers and the sense that their personal satisfaction from the experience serves a (literally) higher purpose. Those outcomes don’t result from most of my hobbies.

When analog astronauts get back, they’re part of a community that understands what they’ve gone through and that is more inclusive and diverse than the space industry writ large. This conference had openly queer people, people of color and women in numbers not typically seen at such meetings. People who attended work as mail carriers, nurses, musicians. At the “Inclusion Discussion Session” one person came out, another spoke of their addiction status, someone else discussed having been homeless, another brought up her impostor syndrome, and others talked about harassment. There were tears. After all, even astronauts cry sometimes. I’m not an astronaut, and I did so while listening.

“How many people have gone to a space conference?” asked Sian Proctor, the conference’s co-founder and an astronaut in both the analog and literal sense, at one point. Many people raised their hand. “How many people have gone to a space conference that looks like this?” Proctor said. No hands went up.

Analog astronaut experiments are, in some ways, all about pretending we already live in the kind of future these conference participants want—one with rich life beyond Earth. And that rich life includes more and different people than it has in the past, just like the Biosphere 2 meeting did. I’ve come to see how simulating this better future is valuable, even if humans never set up cities on Mars and even if the effects are self-contained and limited to a small group here on Biosphere 1.