 Over the past decade, NASA's National Space Technology Laboratories, NSTL, in Bay St. Louis, Mississippi, has been doing plant-related research in purification of air and water for when people begin living in space. Many communities, including the city of San Diego and Disney's Epcot Center in Florida, have adopted research done at NSTL by using a plant called the water hyacinth in their treatment of raw sewage. This common weed, the water hyacinth, literally thrives on sewage. The plant has a complex roof mass, which acts like a filter. Bacteria and microorganisms that grow on the root system break down and digest the sewage, allowing the hyacinth to absorb nutrients, toxic chemicals, and even radioactive waste. The effluent that comes out of this system, which has treated sewage for a couple of days, is of such high quality that it needs only to go through a few final steps before it is drinkable. The hyacinth dislikes cold water, but when in a warm climate, it grows at such a furious rate that it needs to be harvested on a regular basis. Once harvested, the plant matter can be dried for animal feed or shredded and loaded into a digester for further processing into biogas, which can be used as a fuel. The city of San Diego's Water Utilities Department has adopted the use of water hyacinth in a large-scale project to reclaim raw sewage and process it into drinking water. Another plant-related water filtration system recently developed through research at NSTL is called a rock reed filter. In this case, polluted Mississippi River water passes through granular rock containing reed plants. The roots from the reeds and the high surface area of the rocks support bacteria that break down pollutants and purify water. Since reeds can tolerate cold weather, this system works very well in regions where water hyacinths can't grow. The latest research at NSTL has been with a spider plant system that purifies air along the same lines as the rock reed filter does for water. Air is purified as it's gone through the spider plant, interacting with activated carbon and the plant's root system. Dr. Bill Wilburton of NSTL. Now this is an exciting new technology that's emerging that we're looking at now. It not only allow fewer plants inside a home to purify that air, but it has tremendous applications for our future space station as we look towards developing a space station or a moon base or others. So these technologies evolving from aquatic plants to common house plants, we're beginning to put this technology together for practical, simplified everyday use with the ultimate long range goal of perfecting a closed ecological life support system for a space application, be it a moon base or a space station.