In the small town of Oracle, Arizona, in the foothills of the Santa Catalina Mountains at an elevation of 4,000 feet, stands a unique 3.14-acre complex called Biosphere 2. It is less than an hour from Tucson, and the only way to get there is by car. Even after more than 32 years, it continues to attract many visitors. As an American Earth system science research facility built to be an artificial, closed ecological system and designed to prove the viability of such systems to support human life in outer space, it is today still the largest such closed system ever created. As a matter of fact, it has grown over the nine years between our three visits, and here are the reasons why we keep going back.
The Impressive Glass Pyramid
By our third visit, there was already a Biosphere 2 app, an easy-to-use tool for a self-guided tour. As soon as you get out of the parking lot, you are reminded to download it to your phone. No worries if you run into some problems; the receptionists at the spacious Welcome Center will help you complete the task. Actually, it can even be downloaded in the comfort of your home or office before your trip. If you do, you’ll be able to listen to the pre-tour podcast of the natural history of the area around Biosphere 2.
Right after passing the many casitas, a café, and other facilities that comprise a sizable conference center, you will be impressed by a huge glass pyramid. You have reached Biosphere 2. These questions popped into my mind: “Why Biosphere 2? If there is a 2, what then is Biosphere 1?” That glass pyramid was created to mimic Biosphere 1 (our Earth). It was an amazing venture constructed between 1987 and 1991, funded by the Texan billionaire and philanthropist Edward Bass, who put in $250 million.
Designed by systems ecologist John P. Allen, it is made of steel tubing and high-performance glass and steel frames. The window seals had to be almost perfectly airtight so that air exchange would be extremely insignificant to allow the tracking of subtle changes over time. During the day, the heat from the sun causes the air inside to expand, and during the night it cools and contracts. The section on “Technosphere” below will explain how “lungs” were used to manage this. Since the windows should not be opened, it also describes how temperatures are regulated for each of the different biomes. It is an amazing feat of engineering!
Six Of The Seven Biomes
Seven biomes were created to be jointly housed under that glass pyramid. The five ecological systems included are a 20,000 square-foot tropical rainforest, a 9,100 square-foot coral reef ocean, a 4,800 square-foot mangrove wetland, a 14,000 square-foot savannah grassland, and a 15,000 square-foot coastal fog desert. It was amazing to see the widely different kinds of plants supported by all those ecosystems under one roof. They used to support animals too.
On our last visit, we entered the fog desert first; it was the reverse in our first and second visits. Because it was spring, the desert was blooming with flowers. Then we moved on to the savannah grassland, which gently transitioned into a mangrove wetland where we were surprised by light showers. The next biome was the ocean with coral reefs. During our first and second visits, we were able to view the ocean as a huge aquarium from below, but it was closed because of COVID during our last visit. As we stepped into the tropical rainforest, we were welcomed by a waterfall and a lush forest with giant plants and trees.
In addition to these five biomes, there is a 27,000 square-foot agricultural area constructed to study the interactions between man, farming, technology, and nature. A new Lunar Greenhouse, a second prototype of the Controlled Environment Agriculture Center, seeks to understand how to grow vegetables on the Moon or Mars by developing a life support system that recycles water through plant transpiration (sweating).
The Seventh Biome: Biospherians’ Apartments
The seventh biome is the human habitat. The first closure experiment was conducted from 1991 to 1993 involving eight humans (four men and four women) called “Biospherians.” On our first and second visits, we were able to visit the three floors that housed their apartments, which included their spacious kitchen and dining area, their living room including a library, and their individual bedrooms. Unfortunately, because of COVID, this part was not open to visitors during our last visit.
Agricultural tasks occupied much of the crew’s daily routine since they were expected to produce their own food. They kept detailed records on what they produced and the changes in the biomes and atmospheric conditions. The experiment was heavily publicized, but it ran into problems. There were unstable amounts of food and oxygen, and some of the animals and plants died. Worse was the tension that developed among the Biospherians who split into two factions. Finally, outside Biosphere 2, there was a power struggle over the management and direction of the project. However, it was still considered successful because world records were set in agricultural production, health improvements, and insights into closed ecological systems.
In March of 1994, after upgrades and improvements in system engineering and the introduction of additional species into the ecosystem and agricultural areas, the second mission with a crew of seven began. But this also ended prematurely in September 1994 with tensions in the management and financing of the project. This second closed experiment, however, achieved total food sufficiency and did not require the injection of oxygen, unlike the first.
The LEO: Landscape Evolution Laboratory
The managing company, Space Biosphere Ventures, was dissolved during the middle of the second experiment. Columbia University assumed management of the facility from 1995 until 2003. The biosphere then teetered on the brink of closure. In 2007, the University of Arizona took over the research portion. In 2011, they took full ownership with the help of private donations and funding. The university proceeded to expand it.
They added the Landscape Evolution Observatory (LEO), which uses almost two thousand sensors to monitor millions of pounds of volcanic rock. It was built to track how nonliving soil slowly develops over several years into rich soil by supporting microbial plant life. Three large steel-framed and glass-enclosed “hillsides” inside the pre-existing domes were built as the world’s largest device to measure the amount of actual transpiration by plants.
The Technosphere Below And Outside
All that you see aboveground is amazing, but wait until you inspect what is belowground! The following may be a bit technical, but it is an attempt to explain how this biosphere is maintained. The technical infrastructure manages the environmental conditions of the habitats above. It was open during our first and second visits, but due to COVID, it was closed to visitors when we last visited.
There are more than two dozen air-handler units that control air temperature and humidity, allowing for cooling, heating, water condensation, and dehumidification. Air is circulated to the air handlers from the energy center housed in a building external to the glass-enclosed area. Heating and cooling water circulate through independent piping systems with passive solar input through the glass space frame panels covering most of the facility. Water from condensation within the biosphere is collected in a 200,000-gallon tank where it can later be used for other purposes like putting out fires. The natural gas energy center supplies Biosphere 2 with electrical power with backup generators. There are also systems of solar panels throughout the grounds. Though cooling is the largest energy need, heating also has to be supplied in the winter. Biosphere 2 also contains a biologically based waste-treatment system.
What interested me the most are the two large aboveground domes that contain the “lungs.” As external temperatures rise and fall, air remains trapped or is released from them. This release produces pressure that may exceed the strength of the glass if not controlled. The lungs are large expansion chambers that regulate the air pressure above. Each lung is connected to the biosphere by a tunnel. It consists of a heavy metal plate attached to a rubber membrane which is made to move up or down. It was so interesting to witness!
Biosphere 2 was an experiment to gain knowledge about the use of closed biospheres for what we think may be needed for future space colonization. As an experimental facility, it allowed the study and manipulation of a smaller system without having to harm the Earth’s biosphere itself. Today, it is an ongoing research facility, a campus for educational programs, a conference center, and a one-of-a-kind museum that is a must-see for young and old alike.
Pro Tip: It would be best to check which facilities are available for visiting before you go. Some of the best features were not open during the last time we visited because of COVID.