NASA is working on a greenhouse system that can potentially allow astronauts to grow plants and vegetables during space missions.
Growing Food On Mars And The Moon
In 2015, astronauts Scott Kelly, Kjell Lindgren and Kimiya Yui ate the first food grown in space - red romaine lettuce - that they seasoned with olive oil and balsamic vinegar.
While astronauts at the International Space Station have already successfully grown plants and vegetables on board the orbiting laboratory, long-term solutions are needed to sustain people who work in deep space amid plans to send humans to Mars.
Through the Prototype Lunar/Mars Greenhouse project, researchers aim to develop a greenhouse system that can work on Mars or the moon. The project conducts research on growing vegetables in space for food and cultivating plants that would sustain life support systems.
Researchers from the University of Arizona in Tucson, who work with NASA scientists to develop long-term solutions for food production in space, conduct Prototype Lunar Greenhouse tests to determine the type of plants, seeds, and other materials that can be used to make the system work on Mars and the moon.
Greenhouse For Martian And Lunar Missions
Researchers are developing systems that can support missions that span for months or years. The bioregenerative life support system involves a deployable and inflatable greenhouse that can support the production of plants and crops for air revitalization, nutrition, waste recycling, and water recycling. Prototypes measure 18 feet long and are over 8 feet in diameter.
"Centered on using plants to sustain a continuous vegetarian diet for astronauts, a typical BLSS employs plants and crop production in addition for food, to also provide air revitalization, water recycling, and waste recycling for the crew," the University of Arizona in Tucson explains.
Greenhouse Mimics Biological Systems On Earth
The carbon dioxide that astronauts exhale is introduced into the greenhouse, where plants can generate oxygen through photosynthesis.
The water that astronauts bring to or find at the lunar or Martian surface is oxygenated and given nutrient salts for the water cycle. It will continuously flow across the root zone of the plants and return to the storage system.
"We're mimicking what the plants would have if they were on Earth and make use of these processes for life support," says Gene Giacomelli from the University of Arizona. "The entire system of the lunar greenhouse does represent, in a small way, the biological systems that are here on Earth."
Specialized Lighting Needed
Greenhouse units that will be sent for space missions will likely be buried under surface soil or the regolith to protect them from radiation in space, which means that these systems would require specialized lighting.
Researchers appear to have the solution as they have already successfully used electric LED lighting to grow plants. Researchers have also figured out how to utilize natural light. Light concentrators tracking the sun may capture solar light and convey this to the chamber with the help of fiber optic bundles.