Lettuce can be safely grown in space using a unique system for plant cultivation in weightless environments, according to a study published on March 6 in Frontiers in Plant Science. The growing system was designed by NASA scientists with the goal of improving astronauts’ traditional diet of dehydrated meats, freeze-dried ice cream, and other processed foods that degrade and become less nutritious over time, according to The Guardian.
Veggie, as the system is called, addresses the unique challenges of watering plants in space “where we can get too much water or not enough water,” coauthor Gioia Massa, a plant scientist at the NASA Kennedy Space Center in Florida, tells The New York Times. “Water coats your surfaces. It will clog the pores of things. It will even crawl up the plants if you have too much water.”
Roughly the size of a piece of carry-on luggage, Veggie holds six plants that grow from seeds embedded in wicks on what the authors call “plant pillows.” These pillows are filled with fertilizer atop a clay foundation that is typically used in baseball fields, reports CNN. The pillows are injected with water, which the wicks then deliver to the seeds. A magenta LED light and a fan contribute to optimal growing conditions for the plants.
In the new study, the scientists looked at batches of lettuce grown between 2014 and 2016. Some of the leaves were eaten by astronauts who cleaned them with sanitary wipes, and others were deep-frozen and analyzed on Earth, according to The Guardian. The researchers found that the space-grown lettuce had a similar composition to Earth-grown lettuce, but was higher in phosphorous, sulfur, zinc, sodium, potassium, and bacteria, likely due to the warm, humid growing conditions, though the plants did not contain E. coli, Salmonella, or Staphylococcus aureus.
“It’s just a rigorous, careful study on the safety of crops grown in space,” environmental plant physiologist Bruce Bugbee of Utah State University who did not participate in the research tells the Times. “This kind of research is really helpful for us to feed people away from the planet Earth.”
“We were delightfully surprised at how much the astronauts enjoyed growing and eating the fresh lettuce!” says coauthor Christina Khodadad of NASA's Kennedy Space Center in remarks to CNN. “The ability to grow food in a sustainable system that is safe for crew consumption will become critical as NASA moves toward longer missions. Salad-type, leafy greens can be grown and consumed fresh with few resources.”
Massa tells CNN that future research will look at growing peppers, tomatoes, and other types of leafy plants in order to add more fresh produce to the astronaut diet.
Amy Schleunes is an intern at The Scientist. Email her at firstname.lastname@example.org.