Researchers at the University of Arizona Controlled Environment Agriculture Center, known as CEAC, have built a prototype lunar greenhouse demonstrating that plants from Earth could be grown hydroponically (without soil) on the moon or Mars.

The prototype represents the last 18 feet of one of several tubular structures that would be part of a proposed lunar base. The tubes would be buried beneath the moon’s surface to protect the plants and astronauts from deadly solar flares, micrometeorites and cosmic rays. The membrane-covered module can be collapsed to a 4-foot-wide disk for interplanetary travel. It contains water-cooled sodium vapor lamps and long envelopes that would be loaded with seeds, ready to sprout hydroponically. It includes sensors that gather data, algorithms to analyze that data and a control system to optimize performance. The researchers also trying to devise a remote decision-support system that would allow an operator on Earth to intervene.

But where is the CO2 and water coming from? The scientific answer is: Carbon dioxide is fed into the prototype greenhouse from pressurized tanks, but astronauts would provide CO2 at the lunar base just by breathing. Similarly, water for the plants would be extracted from astronaut urine, and the water-cooled electric lights might be replaced by fiber optic cable – essentially light pipes – which would channel sunlight from the surface to the plants underground.

“We turned the greenhouse on about eight months ago to see how it would operate and that test run will be completed on Sept. 30,” the researchers said.

The UA researchers are funded by NASA and collaborating with two Italian firms on this project: Thales Alenia Space, a company that builds hardware for the International Space Station, and Aero Sekur, which builds inflatable structures.

The research also could lead to plant colonization in another traditionally hostile environment – large urban centers. This is really an exciting research which we will observe in its development.