Ecospheres Associates in Tucson, Arizona manufactures and sells sealed glass balls filled with water containing green algae, other microscopic biota, and tiny shrimp in a symbiotic community that illustrates the principle of closed loop life support in permanently recycling systems. Called EcoSpheres, they come in a variety of sizes from 4 inches in diameter to 9 inches, are priced like small kitchen appliances, and have “replacement periods” of up to a year. With care, they can last for many years. EcoSpheres are a NASA spin-off, the first product of US experiments to create closed ecosystems, ultimately for humans in space habitats.