Biosphere 2 becomes ‘big science’


As you approach the turnoff for Biosphere Road, 30 miles north of Tucson on State Highway 77, you see nothing but the Sonoran desert in southern Arizona and a couple of semi-civilized junk. There is a rock with the Biosphere 2 logo on it. There is a flagpole. From the flagpole, in order from top to bottom, wave (1) that star-studded banner that the current administration in Washington hates so much, (2) the starburst of the copper state of Arizona, and finally, the “A” flag for the University of Arizona.

Turn right (if heading north). I drove a couple of miles past cattle crossings, a copper mine, an electrical substation that has nothing to do with B2, and an empty guard post at the entrance to what was once Sunspace Ranch. Stepping inside, you might catch a glimpse of what Columbia University called “The Appliance” when they ran the place. It ends in a wooded parking lot next to an entrance plaza equipped with fabric awnings. Watch out for snakes.

Just to get you out of the way, note that Biosphere 2 offers “under the glass” tours inside the 3.14-acre biosphere apparatus (the U of A likes to call it “The Sphere”) from 9 am to 4 pm 363 days a year. year, except for Thanksgiving Day and Christmas Day, which they call “December 25”. They do tours even though it snows a little. (Biosphere 2 is 3,900 feet above mean sea level, 1,400 feet above downtown Tucson.) They do this even if the summer monsoons are wreaking havoc on the Catalina Mountain foothills, where the Biosphere is located, as long as it is deemed safe. For ticket prices (around $20), you will have called 520-838-6200. The voice is automated, so you will NOT find out this way that you can get a better deal on membership, as the B2Science website reveals. See “Links” at the end of the article.

The website also explains why people with physical limitations may not be able to take the tour. The stairs are unavoidable. The balance may be uncertain. You have to take care of your head. You have to watch your step. You have to see both at the same time.

Well, it can’t be that bad. More than 100,000 visitors a year come this way, from 100 per day or less in the summer months, when tours run within 1 hour and 15 minutes, to 900 per day in the winter, when tours begin. every 15 minutes. Add in the ten minutes or so it takes to get to the starting point, and you should allocate 90 minutes to the tour, not counting bathroom breaks, shuffling through underwater caves to see the man-made ocean floor. , or visiting what was the human habitat when Biosphere 2 was the home of the “biospherians”. Fifteen biospheres in two “missions” lived there under simulated space colony conditions from 1991 to 1994. There is a souvenir shop. There is a “café”, but its offer is limited, as are its hours. If you’re not in a rush, Biosphere 2 is good for 2.5 hours.

You start the tour with a 10 minute movie. Make a headline call if you don’t care about the party line, because it’s all about political imagery. It instructs the viewer that the “Sphere” is the only place where certain experiments can be performed, and therefore the U of A must control the Sphere, or the world will end. You’ll hear that over and over again, throughout the ride. If you question the concept, you’ll hear it one more time, along with the words “I said that,” so don’t torture the tour guide.

Pay attention to the signs posted everywhere proclaiming that the Biosphere is now, thanks to the University of Arizona, “Big Science.”

Be that as it may, Biosphere 2 is a feat of engineering. That becomes clear when your guide points out construction details such as the triple-pane hermetically sealed glass and steel structure, cave-like air registers and massive returns, rain pipe network on top, and the machine. of artificial ocean waves. The tour will include a visit to the “Technosphere”, mastery of air controllers, coolers, pumps, tanks, reverse osmosis filters, circuits and pipes. Above, you’ll have noticed that the rainforest might be running at 120 degrees Fahrenheit with 90% relative humidity, while the coastal desert is 85 degrees with 25% humidity. Each biome has its own independent environmental control system in the Technosphere.

Although the temperature inside the glass must vary with time of day and season to mimic that on Earth, it is essential that the pressure variation inside the glass not exceed the resistance limits of the glass (Charles Law, people, chemistry high school). The problem is solved by using two dome-covered “lung” structures to the south and west of the main Biosphere. Inside each protective white dome, there is a cylinder covered by a rubber (Hypalon) diaphragm that lifts a central weight. Both the diaphragm and the disc-shaped weight form the roof of the vast cylinder connected to the biosphere by a tunnel. The weight controls the pressure and the diaphragm rises or falls like a piston to convert what would otherwise be a pressure change into a volume change as it rises and falls throughout the day (Boyle’s Law). Your tour will visit the southern lung, with its added feature of a 250,000 gallon reservoir to collect “rainwater” for recycling. With a pair of massive pumps visible above the central pool on the floor, the depot also provides firefighting service for the Biosphere.

Leaving the southern lung to the outside world, hold on to your hat. A fierce wind will blow you out when you cross the hatch. That wind will provide your best evidence of positive air pressure within the biosphere.

Later, as you tour the habitat dwellings on your own, be sure to visit the bathroom. You’ll find your usual toilet paper on a roll, but it’ll be in an awkward spot, like your bathroom isn’t designed to hold it. It was not. Note the hose and valve on the wall. it’s a bidet. Biospherians never used toilet paper. The sewage treatment plant was, well, plants, in the saltwater swamp. Everything, including the wastewater, was recycled for closed-loop life support. Today, of course, the bathroom is connected to a standard septic system. That will be your best evidence that Biosphere 2 is no longer closed to the outside.

In fact, Biosphere 2 has been reconfigured to allow certain gases (mainly carbon dioxide) to pass in and out. By this method, the composition of its atmosphere can be precisely controlled, as is necessary to do the kind of science that is done there now. Water is no longer fully recycled. If it were, the isotopic markers used to identify the drain source would be counted twice.

Biosphere 2 is an ecology laboratory, but its appearance and setting retain the romance of its history in a place that, at times, evokes the magnificent desolation of the Red Planet. Only the most passionate and emptied visitors buy the “Big Science” story. They really are going to Mars.

links

http://www.b2science.org

http://biospheres.org