Exploring the Biodome Trope… since we really built one.

Alright sci-fi fans… I hate to burst bubbles here. We’re a long way from self-sustaining bases in space, and especially far from them on other planets. Thankfully we have fiction! In our little fun worlds, we can accept that livable, lush environments can be created, maintained, and transplanted anywhere we want them. That could be on a space ship, star base, or Goldilocks planet just waiting for colonies.

Now, back in real life, and maybe dialing the time travel meter back a few years, people tried this.

That’s my brother in the corner. He’s the main reason I’m a sci-fi nut today.

SPACE BIOSPHERES VENTURES. That’s an actual company that purchased land from a ranch out in Tucson, AZ in 1986 and invested millions to develop “self-sustaining space-colonization technology”.

I went to see it, in person, and I nerded out. This whole thing oozes sci-fi vibes, and it doesn’t help matters that the décor from the 80s totally matches what we (and the makers of star trek TNG) imagined the future to look like back then.

Mostly, I was just losing my mind to be in a place that actually tested what so many sci-fi writers take for granted – that a living biosphere can be replicated and sustain human life.


The whole idea of a bio dome was a popular one, and these guys went all-out. After the project’s completion, they ran missions to determine the survivability of their contained environment. These missions sealed 8 scientists in the closed-system experiment for a period of 2 years. The first mission went the full 2 years, but the second mission came to an early close.

The media called the first mission a failure, but they were looking at this project with the expectation it should succeed in its entirety. Part-way through that first mission, the oxygen levels within the system dipped below safe levels. There were a few good reasons for this, which you can have a look at through the links provided further on.

The project managers eventually decided to pump in more oxygen for the project to continue, though doing this was apparently grounds for the media (and sections of the scientific community) to call the whole thing a failure.

Anyway, there are clarifying details in several articles on the subject, so here are a few:






For further reading, each of the two research papers include a long list of works related to the Biosphere 2 mission. I’m a big advocate of looking at either primary sources or grey literature where you can get it. Research papers give facts skewed only be the original author… vs. layers of authors and hearsay. Have a look at those for more details on the mission.


These days, the purpose of Biosphere 2 has shifted.

The inside of the rainforest biome is pretty crowded. I’d hoped to walk through it, but the walkways only went a few yards inside.

The University of Arizona owns the place now. They’ve turned this massive single-purpose project site into a multi-purpose research facility. Each of the environments now act as controlled experiments where scientists run tests on the effects of climate change and oxygen production.

The rainforest area, now separated from the other environments for more control over its climate, is hot, sticky, and smells like a clean mold. Gross, but awesome. The plant life just booms into every corner of its enclosure, and its vitality is measured against readings taken by partnering researchers in the Amazon basin. In Biosphere 2, they have a constant. In the Amazon, factors of human action and climate shifts cause changes which are easier to measure with a comparison site.

An example of their blue barrel projects.

Our guide didn’t go very in-depth about the programs going on with the savanna and simulated ocean. The walkways installed after the missions, specifically for tours, actually killed the savanna and they have some “blue barrel” projects to see which grass types can flourish in the changed area.

One thing for you sci-fi fans to think about when writing your self-contained environments: sound.

There are no animals in Biosphere 2. Though, now it’s not sealed, a few birds do get in now and then. So the only sound in the rainforest section is the waterfall. And the only noise in the main room, the connected ocean, savanna, marsh, and coastal desert, is an intermittent roar from their resident dinosaur.

The pump is located past the boats in this picture and takes up the whole back portion of the ocean. Lots of gurgling and roaring.

The guide called it by its nickname Dino B2. This is the pump that gives the ocean its oxygen and necessary motion. It’s on 24/7 and is crucial to the life of the biodome. Thing is, every few minutes, it also fills building with a muted, rumbling roar that ricochets through the steel and bounces off the glass at weird angles. This, combined with the resulting lapping of the water against the small shore, makes up the collective sound of the biodome when nobody’s around.


Now here’s the nitty-gritty bit. Walking through that place, it was easy to forget none of it was natural. However, as an Arizona native and a hobby gardener, I was reminded at every turn all of this stuff would be dead without a ton of tech!

Once our tour group made it to the end of the massive environment building, finishing up at the coastal desert, we followed our guide down into the “Technosphere”.

Tunnels, tanks, and pipes run everywhere beneath the whole of Biosphere 2. Each one is labeled: hot water in, cold water out, hot water out, cold water in… They’re all running in and out of condensers pumping every drop of water the plants (and animals, during the mission) need to survive. This was a closed system for the experiment, so every drop of water spent time in each of the environments, being processed, converted, cooled, evaporated, ingested, expelled, over and over during the course of the 2 years. Our guide pointed out some small plastic containers placed under pipes near the floor and told us that water was so precious that all this condensation collected in the Technosphere was used for cooking, drinking, and washing.

The tunnel in the Technosphere.

The guide, after stopping us in a little sitting area in the down-below, explained how the scientists spent most of their day hours farming on the other side of the living facilities in a dedicated agriculture area. They did have to balance that out with work maintaining the system, clearing filters, collecting samples from the various tanks, and generally keeping the Technosphere working.

If the machines failed, they took the whole experiment with them. Thankfully this wasn’t on Mars, or the scientists’ lives would depend on the work.

We’d walked a good way through the underbelly of the place. Before we left, our guide had us look down a hall to give us an idea of the scope of maintenance required of the scientists.

It looked endless, especially in person.

So, take note, sci-fi fans and writers. This project was no pleasure cruise. It basically took this group of scientists right back to subsistence living, with the added pressure of maintaining an ecological system not designed to survive.

For those considering conflicts and challenges of living in an artificial environment like this, the biggest physical discomfort experienced when things started to go wrong in the biodome was fatigue.

The dining and kitchen area of the living quarters.

The crew lived well enough, and the issues they ran into had nothing to do with not eating. Their diet was nutrient rich… but not calorie dense. A low calorie diet gave them less energy. They lost weight, enough to concern those monitoring the experiment.

When oxygen became an issue (see the links I shared before for why), their energy fell even farther. Less oxygen to breathe leads to physical restrictions just like you have in high elevations. Their mental clarity and focus were deteriorating, especially in the days before the controllers’ decision to pump in more oxygen so the experiment could continue.

Here’s a bit for the physics fans out there. What happens when you put additional gas into a closed system?

Pressure increases.

The biodome is glass and steel. Too much pressure inside the dome would cause the glass to crack, violating the sealed conditions of the experiment even more than they already were. So, what to do?

Enter the LUNGS! *dun dun dun!*

The buildings containing each lung are a more “traditional” dome shape. You can see one here on the left.

Biosphere 2 has two lungs. These are rooms that expand and contract to allow excess gasses and volume changes (due to temperature and pressure) to escape the rigid glass buildings, and reenter again when needed.

I don’t know if the oxygen emergency made them build a second lung, or just to activate it as their existing plan for such a problem, but in activating it, they could give the scientists more oxygen without cracking the bazillion panes of glass in their giant greenhouse.

We got to stand in one, and my picture does a PITIFUL job of showing the vastness of this thing.

Envision a massive circular room. In the center, a metal table weighing several tons with edges connected to the upper circumference of the room by a flexible black material. The air, pumped into this room from the biodome, causes the flexible material to expand and lift this table up into the air above your head. When air escapes (as in when someone walks into or out of the lung), you can see this massive weight lower at the rate of a few inches a minute.

I had another shot, but it turned out fuzzy. Sad. Click to see a bigger picture.

Essentially, we stood in a huge doughnut-shaped balloon.

And it was awesome!

Great acoustics in there. Reminded me of one of my favorite scenes in Star Trek when Lt. Cmdr. Nella Darren used a junction of the Jefferies tubes as a mini concert hall.

Only the lung is big enough to be a full concert hall.

Our tour wrapped up once we exited the lung, leaving the group to trek back up a lot of stairs back to the visitors’ center. I’m still a little sore from all the stairs. But I wouldn’t trade that visit for anything! Where else in the world can you get so close to the space habitat of our sci-fi dreams?

If you’re planning a visit to Arizona and want to include Biosphere 2 as part of your trip, it’s located just north of Tucson, about 3 hours’ drive from PHX airport. Visit their website for directions, hours, information, and more about what the University of Arizona is studying within the biodome.


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