Life Under Glass: The Biosphere 2 Exit

This is the Daily Brief, and I’m Michael. The date is September 26, 1993. We are live in Oracle, Arizona, witnessing a moment of strange history. Behind me stands the shimmering, three-acre glass ziggurat of Biosphere 2. For the last two years, eight men and women have been sealed inside this airtight terrarium, completely cut off from Earth’s atmosphere, recycling their own water, growing their own food, and breathing the same recycled air.

Moments ago, the airlock unsealed. The crew stepped out into the blinding Arizona sun, looking thin, pale, but elated. Joining me now, still adjusting to the raw atmosphere of what they call 'Biosphere 1,' is one of those crew members, Susan. Susan, welcome back to Earth.

Thank you, Michael. It’s... it’s overwhelming. The first thing that hits you isn't the sight of people, it’s the smell. The outside world smells incredibly complex. Dirt, sagebrush, exhaust, perfume—it’s an assault on the senses. inside, the air was scrubbed clean, almost sterile, except for the scent of agriculture. And the air out here... it feels thick. You can actually feel the weight of it in your lungs.

That thickness is something I want to ask you about immediately. We’ve heard reports that the oxygen levels inside the facility dropped dangerously low, to the point where it was like living on top of a mountain. What was happening in there?

It was a mystery that nearly ended the mission. We were gasping for breath. Imagine waking up every day with a pounding headache, unable to finish a sentence without pausing to breathe. Our oxygen dropped from a normal 21 percent down to about 14 percent. It was physically like living at 14,000 feet elevation. We were dragging ourselves up the stairs. We knew we were losing oxygen, but we couldn’t find it. The math didn't add up. The plants should have been producing enough, but the numbers kept falling.

Did you find the culprit?

We think so. It wasn’t a leak. It was the building itself. The soil we brought in was so rich in organic matter that the microbes went into overdrive, munching on it and pumping out carbon dioxide. But here’s the twist: the concrete walls of the Biosphere weren't fully cured. The concrete was actually absorbing that carbon dioxide and locking it away as calcium carbonate. In a way, the building was eating our air. It was suffocating us.

That sounds terrifying. You’re trapped in a glass jar that’s slowly asphyxiating you. And yet, the psychological pressure might have been even worse. There are rumors of a severe split among the crew.

'Split' is a polite way to put it. Michael, imagine being stuck in an elevator with seven other people for two years. Now imagine the elevator is running out of air and you’re all starving because the sweet potato crop failed. The stress fractures were inevitable. We broke into two groups of four. It wasn't just a disagreement; it was a cold war. For months, we barely spoke to the other side. We’d pass each other in the kitchen, silently plating our meager rations of beets and bananas, and not say a word. It’s what psychologists call 'confined environment psychology.' The isolation distorts your reality. The people on the other side became the enemy, not the situation.

And while you were fighting this internal cold war, the ecosystem around you was waging a war of its own. We heard about the pollinators dying off?

That was heartbreaking. We lost the hummingbirds. We lost the honeybees. Without them, we had to hand-pollinate the crops ourselves. But while the good insects were dying, something else took over. We call them crazy ants—Paratrechina longicornis. They are these tiny, erratic ants that don't march in lines; they just swarm frantically. They exploded in population. They were everywhere. In our beds, in our food, shorting out the electronics. They decimated the other insect populations. It was a lesson in how fragile a closed system really is. You lose one balance, and a single invasive species just conquers the whole world.

You sound exhausted, Susan. Was it a failure?

A failure? No. If we had gone to Mars and this happened, we’d all be dead.

"Because we did it here, we learned that concrete eats oxygen. We learned that crazy ants can collapse an ecosystem. We learned that human psychology is just as volatile as atmospheric chemistry. We survived. We’re skinny, we’re breathless, and we’re wary of each other, but we survived. That’s the data."

Susan, thank you for speaking with us. Go get a cheeseburger. You’ve earned it.

I plan to, Michael. I plan to.