In the summer of 1973, a trio of astronauts aboard Skylab -- the United States' first-ever space station -- used air testing instruments to see what they would be breathing during their two-month stay in space. The results were worrying: Skylab's air was filled with trace amounts of more than 100 harmful chemicals.
The space station was made from some of the world's most cutting-edge synthetic materials: plastics, polymers and resins. But while processed materials make for good space stations, they make for lousy air. The materials were emitting small amounts of toxic gas, a phenomenon known as "off-gassing." It's not like the Skylab astronauts could open a window, so for their next 58 days in space, the astronauts simply had to breathe in a swamp of carcinogenic chemicals.
A few hundred miles below, earthlings were having a similar problem. In the face of skyrocketing energy costs during the late 1970s, office buildings in the United States were being built to much higher environmental standards. Rather than working in drafty brick and steel structures, Americans were now going to work in well-insulated office buildings. The buildings were better on heating costs, but their stale, recirculated air was a trap for off-gassed chemicals that caused office workers to develop itchy eyes, skin rashes, drowsiness and breathing problems. Soon, about 30 percent of office buildings were giving workers what came to be known as "sick building syndrome" [source: Environmental Protection Agency].
In the late 1980s, NASA decided to tackle the problem of indoor air quality by calling in Bill Wolverton, an environmental scientist who had done cleanup work for the U.S. military. Equipped with a rich background in plants, Wolverton settled on the relatively simple solution that indoor air quality could improve with a little vegetation. Plants like peace lilies and bamboo shoots looked great in a living room, and Wolverton was sure they could also neutralize toxic gas.
To test Wolverton's theory, NASA engineers put together the BioHome, a heavily-insulated structure about the size of a mobile home built almost entirely from synthetic materials. The BioHome's plastic walls off-gassed so heavily that anybody walking inside was immediately stricken with burning eyes and breathing problems. That is, until engineers crammed the structure with houseplants. Within days, they found, the structure's interior was as fresh as a daisy.
NASA published its results, and offices around the world soon were using indoor foliage to stave off employee headaches and skin rashes.
Keep reading to find out how NASA used bits of silver to deliver fresh water to moon astronauts.
Clean Water, NASA-style
Plants can't just suck out pollution; they can clear up dirty water, too. The BioHome also came equipped with a plant-based sewage system. Instead of being chemically processed, sewage would just be diverted through a long piece of plastic pipe stuffed with aquatic hyacinths. By the time the sewage made its way through the maze of plants, the water was so clear of bacteria and impurities that it could be used to water a garden. NASA's John C. Stennis Space Center in Missouri still uses this method to process its sewage.
But the hyacinths weren't NASA's first foray into simplified water purification. In the 1960s, Apollo astronauts got their drinking water from onboard fuel cells. The cells created electricity by mixing together hydrogen and oxygen, and water was simply a convenient by-product. But before astronauts mixed fuel-cell runoff into their Tang, NASA wanted to first run it through a filter to kill any possible waterborne bacteria. On Earth, water purification was a relatively cumbersome process; you'd either need to boil the water or run it through a set of bulky filters. Since neither would be possible in the cramped, low-power environment of a space capsule, NASA instead invented a device that would kill bacteria by shooting the water full of negatively charged silver atoms. The particles would latch onto bacteria, destroy them, and then be filtered out of the water to be used again. It was essentially an electronic water purification device. Since it was no bigger than a pack of cards, it was also extremely portable.
After Apollo, a company in north Georgia got the commercial rights to the technology and soon adapted it for use everywhere, from public fountains to commercial pools to zoo tanks. If you've gone swimming at a YMCA or seen the decorative fountains at Disneyland, you've seen water that's been purified the same as it was on the way to the moon.
In 2008, the International Space Station welcomed a completely new type of water purification. For years, the station had received its water from regular space shuttle shipments, but with the shuttle program phasing out, astronauts knew they'd need to be more frugal with their water. Their solution was to start drinking urine. Starting in 2008, astronauts aboard the International Space Station began getting their drinking water from an onboard system that takes urine, sweat and tears and processes it into potable water. It may sound gross, but the cutting-edge system can effectively recycle up to 95 percent of all onboard water -- making regular water deliveries a thing of the past.
Urine-converters are probably a long way from ending up on the shelves at your local hardware store, but if NASA ever decides to venture deeper into the solar system, they'll be glad they brought along a machine to turn "yesterday's coffee into today's coffee" [source: Atkinson].
More Great Links
- Atkinson, Nancy. "Mr. Fixit in space invents zero G coffee cup." November 24, 2008. (March 20, 2011)http://www.universetoday.com/21442/mr-fixit-in-space-invents-zero-g-coffee-cup/
- Barry, Patrick L. "Leafy Green Astronauts." April 9, 2001. (March 16, 2011)http://science.nasa.gov/science-news/science-at-nasa/2001/ast09apr_1/
- The Boeing Company. "NASA explores. Humanity benefits." (March 16, 2011)http://www.boeing.com/companyoffices/aboutus/
- Clean Air Gardening. "Top Houseplants for Improving Indoor Air Quality." (March 16, 2011) http://www.cleanairgardening.com/houseplants.html
- NASA. "Plants Clean Air and Water for Indoor Environments." 2007. (March 16, 2011)http://www.sti.nasa.gov/tto/Spinoff2007/ps_3.html
- NASA, Office of the Chief Technologist. "Water Treatment Systems Make a Big Splash." 2004. (March 20, 2011)http://www.sti.nasa.gov/tto/Spinoff2004/er_1.html
- National Interior Plantscape Association. "Plants Clean Pollutants from the Air." (March 16, 2011)http://www.nipa.asn.au/articles/article1.htm
- Rogers, Simon. "Nasa budgets: US spending on space travel since 1958 UPDATED." February 1, 2010. (March 19, 2011)http://www.guardian.co.uk/news/datablog/2010/feb/01/nasa-budgets-us-spending-space-travel
- Tarran, Jane. Torpy, Fraser. Burchett, Margaret. "Use of living plant pots to cleanse indoor air - research review." Faculty of Science, University of Technology Sydney. 2007. (March 16, 2011)
- Environmental Protection Agency. "Indoor Air Facts No. 4 (revised) Sick Building Syndrome." Sept. 30, 2010. (March 20, 2011) http://www.epa.gov/iaq/pubs/sbs.html
- Wolverton, B.C. Johnson, Anne. Bounds, Keith. "Interior Landscape Plants for Indoor Air Pollution Abatement." September 1989. National Aeronautics and Space Administration, John C. Stennis Space Center.
- Wolverton Environmental Services, Inc. "Indoor Air Pollution." (March 16, 2011)http://www.wolvertonenvironmental.com/air.htm