The University of Arizona

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UA veggie garden for space readied for an earthly trek
Tuesday, June 12, 2012
Mark Armao

A greenhouse designed for extraterrestrial use is taking a more terrestrial trip this summer.

Someday, the University of Arizona's Lunar Greenhouse will provide a life-support system for astronauts on prospective missions to the moon, Mars and beyond. But before it gets to the moon, the Lunar Greenhouse is hitting the road.

Designed by a team at the University of Arizona Controlled Environment Agriculture Center, the greenhouse is being exhibited at the San Diego County Fair, followed by a stopover at the Museum of Science and Industry in Chicago.

"This is for rocket technology, but it's not rocket science," said Lane Patterson, lab manager and researcher for the project.

The goal is to show vegetables can not only be grown in space, but can also supply astronauts with oxygen and clean water, he said.

A prototype has been operating at UA's Campus Agriculture Center since 2010. Inside, vegetables climb the walls of the 18-foot-long cylinder with aluminum ribs covered by a durable plastic skin. Picture a really big slinky with plants inside.

The structure collapses into a 4-foot-long disk for spaceflight. Upon landing, the greenhouse would expand like an accordion and begin to operate.

The greenhouse grows plants hydroponically, which means without soil. Seeds take root in a nutrient-rich solution contained in a flexible plastic tube.

"We're working mostly with vegetables that NASA has interest in; that's leafy green vegetables -lettuces and spinaches and small green herbs like basil," said Gene Giacomelli, director of the program and a plant sciences and engineering professor. The team also is interested in vining plants like tomatoes and root crops like sweet potatoes.

Food isn't the only benefit.

"Each one of them (plants) can provide the water and the oxygen for one astronaut every day," Giacomelli said.

It works like this: The plants absorb carbon dioxide, which astronauts breathe out. And then release oxygen, which astronauts breathe in. In addition to revitalizing the air, the Lunar Greenhouse would recycle water. Eventually, the system would provide clean water by cycling distilled urine through the plants, and collecting the water vapor the plants give off. The intent is to conserve resources and reduce waste.

The lack of atmosphere on the moon presents other challenges, as well. The Lunar Greenhouse would have to be buried under a layer of lunar soil to protect it from micrometeorites and solar radiation. This means artificial lighting is a crucial factor for the project. Proposed lighting options include using energy-efficient LEDs, and piping sunlight into the greenhouse via fiber optic cables, Giacomelli said.

Webcams and sensors in the greenhouse would allow operators on Earth to monitor and manipulate the conditions inside the Lunar Greenhouse.

Giacomelli said the technology has plenty of applications on Earth.

"If a greenhouse is just being installed in Northern Africa, for example, where they've never had a greenhouse before. We do not have to be there to help them grow," he said. "We can stay in Tucson and give them advice from the web camera from the data on the computer and help them grow the crop."

The project is funded through NASA's Ralph Steckler Space Grant Colonization Research and Technology Development Opportunity.

The team has positioned a webcam in the lab that anyone can view online. Team members have addressed entire classrooms though the webcam - from local third-graders to Australian graduate students. "Rather than taking the classroom to the lab, we're taking the lab to the classroom," said Patterson.

What's heading to San Diego and Chicago is a teaching module similar to the Lunar Greenhouse to raise awareness about the project and how to garden hydroponically, Giacomelli said.

As for the Lunar Greenhouse and its prospective trip to space, no specific benchmarks have been set. Funding for the Lunar Greenhouse comes from a special foundation, so recent budget cuts at NASA have not directly affected the project.

Patterson is confident in the system's capabilities, and where the outreach program is headed.

"It's about keeping you alive," he said. "Period."