Published: 
Jan 20, 2016

Historic Vegetable Moment on the Space Station

On August 10th, astronauts on the International Space Station sampled their first space-grown salad and pronounced it “good.” They were treated to freshly harvested red romaine lettuce grown in the “Veggie” plant growth chamber—a special structure designed to make gardens flourish in weightlessness.

On Earth, garden florae battle such foes as cutworms, aphids, slugs, root maggots, blights, and rots. But weightlessness is one thing no Earthly vegetation encounters. In a weightless environment, there is no up and down, so roots grow in all directions. Water and substrate, the materials used to anchor these plants and allow for root growth, tend to float away.

With Veggie, these problems are solved by using 'plant pillows’ -- bags of substrate with 'space dirt' and controlled-release fertilizer. Wicks are implanted in the bags to draw water into the substrate and provide a place to glue the seeds, which are oriented so roots will grow 'down' into the substrate and shoots that emerge will push out of the bag.

LEDs furnish light for photosynthesis and give the shoots a sense of direction so they keep growing upward. The walls of the Veggie chamber can expand to make room for the growing crop.

According to astronaut Scott Kelly’s taste buds, this special space-tailored arrangement works.

“It tastes good, kind of like arugula,” he says, chewing his first bite of space-lettuce. He explains the importance of growing such culinary delights in space.

“…if we’re going to go to Mars someday, …there’s going to be a long period of time where we’re going to have to be self-sufficient …and having the ability for us to grow our own food is a big step in that direction.”

The astronauts celebrated the historic vegetable moment by toasting their lettuce leaves and shouting “cheers.” Before long, they’ll be toasting cabbage, tomatoes, and more. The next SpaceX delivery will supply some of the seeds.

“We will be sending up … [seeds for] a small cabbage that is very highly rated for flavor, and additional red romaine lettuce,” says Gioia Massa, Veggie payload scientist at Kennedy Space Center. “We are working on crop selection with dwarf tomatoes and dwarf peppers….”

Upcoming experiments will use various ratios of red and blue lights and different fertilizers in attempts to improve crop yield, nutrition, and flavor, both on Earth and in space. Other botanical treats are planned for the astronauts as well.

“We have additional seeds on board the station,” says Massa. “These are zinnias--really pretty daisy-like flowers that help us understand longer duration growing plants that have to flower in space such as tomato.  We hope to have flowers in January.”

That kind of enjoyment is expected to be an important added bonus to Veggie.

“I think the psychological benefit of growing plants in space will be incalculable,” she says. “Having living plants could help with stress and increase the crews’ enjoyment. Growing plants can … provide the sights, smells, and tastes of Earth. Fresh produce could add variety and interest to the diet, and the textures of fresh vegetables (crunchy, juicy) could add a new dimension to the packaged diet.”

Scottish poet Alexander Smith said it best:

 “How deeply seated in the human heart is the liking for gardens and gardening.”

Apparently the same is true of human hearts … in space.

For more from the International Space station, go to www.nasa.gov/station

For more nutritious news from Earth orbit, and beyond, stay tuned to science.nasa.gov