Multipurpose Module This collapsible greenhouse, meant for growing produce in space, could be useful in urban centers.
Credit: Courtesy Controlled Environment Agriculture Center at the University of Arizona
Its space shuttle program may be discontinued, but NASA isn’t ready for history’s scrap heap yet. The agency has requested budgets totaling $100 billion through 2015, and its proposed “significant and sustained investments” would include “transformative technology development and flagship technology demonstrations to pursue new approaches to space exploration.”
Recently, NASA extended grants for another two years to the University of Arizona’s Controlled Environment Agriculture Center (CEAC), which focuses on the science of hydroponics in controlled settings, the method of growing plants without soil within structures such as greenhouses.
CEAC scientists and Sadler Machine Co. of Tempe, Ariz., have developed a collapsible greenhouse, an 18-foot-long, membrane-covered module that can be compressed into a 4-foot-wide, 8-foot-diameter disc for storage during lunar or interplanetary travel.
What does any of this have to do with building houses on Earth? Well, since 2004, a 240-square-foot “food growth chamber” that CEAC developed for the National Science Foundation’s Amundsen-Scott station at the South Pole has been growing 30 to 60 pounds of produce per week.
Dr. Gene Giacomelli, CEAC’s director, envisions hydroponic technology being applicable eventually in other inhospitable environs such as urban centers, where freshly grown produce is often hard to purchase. Phil Sadler of Sadler Machine adds that downsizing cities such as Cleveland and Detroit have thousands of vacant lots that could be put to expeditious use by installing hydroponic greenhouses on them.
Urban greenhouses have challenges that include available sunlight and water. The lunar greenhouse, for example, contains about 100 kilograms of wet plant material, or the equivalent of 90 liters of water. But it also “gives back” 53 quarts of drinkable water, and the plants produce enough oxygen to sustain one person per day, thereby creating what Giacomelli calls a “bioregenerative life support system.”
The biggest challenge, though, is the expense of growing produce this way. It costs about $50 per pound of vegetables at the South Pole station. Giacomelli estimates the cost would need to come down to 50 cents per pound to compete with conventional farming.
Still, more people are willing to pay for better-grade food. “In a greenhouse, you’re self contained, and you can control the food safety, the quality, and consistency more easily than in the field.” He adds that pesticides aren’t necessary for hydroponic growing within greenhouses.
And those builders who see them-selves building condos on Mars some day, take heart: CEAC and NASA haven’t abandoned the dream of colonization, for which Giacomelli says a bioregener-ative life support system would be “essential.”