In the fall of 2010, scientists launched a lunar greenhouse. It’s not actually on the moon – it’s at the University of Arizona. Gene Giacomelli, director of the school’s Controlled Environment Agriculture Center, described how the greenhouse might help feed astronauts on a moon mission in the future. Giacomelli told EarthSky:
When the spacecraft sets down, the idea is that it expands outwards, opens by itself, like a robot would. The seeds are already in place. We start it up, turn on the lights, turn on the water, and the plants can begin to grow, even in advance of when the astronauts arrive.
He said a greenhouse on the moon would get water from the moon itself, as well as from cleaned and recycled human waste. Same with carbon dioxide, which plants need to grow. He said:
In this small confined space, growing many, many plants, we can keep one person alive with oxygen and fresh water per day, and half of their food calories per day.
Giacomelli much further development is needed before any kind of greenhouse is sent to the moon, But right now, his hi-tech greenhouse is growing fresh vegetables at the South Pole. And, one day, he said, it might also be applied to enclosed urban structures like skyscrapers. Dr. Giacomelli clarified that this greenhouse is hydroponic – that is, no soil is used – just water and nutrients. He said a greenhouse on the moon would need to get its water from the moon, and also the recycled waste of humans. That is, urine and wash water. It’s safe if properly cleaned, he said, and necessary.
The water has to be found on the planet. Some can be brought. Fortunately, spacecraft have already found water frozen water on the moon and Mars. This water would be melted and then used. But you don’t have an unlimited supply of that water. In fact, you have very little, and it’s very expensive.
Giacomelli added that, in addition to water constraints, there are also light constraints. A greenhouse on the moon would need to be placed underground. He explained how the lighting would get there.
The light will come from one of two sources. One is getting light from a solar collector which will be facing the sun. The light rays will be directed to a fiberoptic cable – which is basically a light tube – and it will bring it from above the surface of the moon or Mars down to the plants growing beneath the surface. The other alternative is to use photovoltaics, a solar collector that makes electric power, electrical energy. That electricity is fed to lamps inside the lunar greenhouse, and gives the plants the light they need to grow.
He said his project is based on a greenhouse his team built at the South Pole – like the moon, an extreme environment.
To get to this point, we did a preliminary project at the South Pole. There’s a food growth chamber located at the National Science Foundation research center at the South Pole and for the past 5 years, it’s been growing fresh vegetables for the people who are living and working there.
Giacomelli explained that the extreme conditions of the South Pole helped his team fine-tune their lunar greenhouse, and also allowed them to figure out how to remotely control conditions like temperature, humidity and light. He said similar technologies could also be used someday in cities – in a greenhouse in the middle floor of a skyscraper, for example. He added that, at least right now, the technology, and lighting, especially, are too expensive for daily commercial use. Dr. Giacomelli told EarthSky that construction of University of Arizona’s lunar greenhouse was truly a team effort. He had help from R. Lane Patterson of the University of Arizona, Phil Sadler of the Sadler Machine Company, and NASA.
Beth Lebwohl researches, writes and helps produce science content in audio and video formats for EarthSky. She is one of the authors on EarthSky.org, a script-writer for our podcasts, and helps host our English science podcasts in 90-second, 8-minute and 22-minute formats. Beth came to EarthSky in 2006 from the American Museum of Natural History's Department of Astrophysics, where she was surrounded by some of the greatest telescope-building, equation-wielding, code-writing physicists of our time. And they made her think . . . this science thing . . . it's pretty cool.