Posted August 12, 2015

Here, have some space-grown lettuce!

Check out this wonderfully surreal scene. Somebody uses a pair of scissors to cut some lettuce, in weird purple lighting, with a narrator announcing: 'Standing by now for the first consumption of red romaine lettuce leaves, grown in the microgravity of space.' It sounds as if a major rocket launch is next.

Then three weightless guys toast with their lettuce leaves and eat them raw, declare them to be 'awesome,' while the narrator dryly notes: 'Eleven forty-six am central time, the crew consumes the first space-grown produce aboard the International Space Station.'

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This happened last Monday. The lettuce was red romaine lettuce, grown in an experimental setup called Veggie inside the space station. It wasn't the first batch of lettuce by the way, for almost a year ago there was a first crop. This was shipped to Earth for investigation. NASA wanted to know, among other things, about possible harmful space-grown microorganisms. This time the crew got permission to eat some of the salad, while what remains will be frozen and sent home for more research.

Growing vegetables is slowly becoming routine in space. The Veggie apparatus incorporates some techniques that have been shown to work. Seeds are sown not in soil but in some kind of gel, because soil crumbles and makes a mess in  weightlessness. There's no up or down but it turns out plants grow neatly away from the gel surface, while the roots do the same in the opposite direction. The roots even radiate outward just like they do back on Earth. Plants need light of course, and red and blue colors are best for growth. (That's why plants look green - they absorb a lot of red and blue from sunlight and most of the green is reflected.) Hence the purple glow of the Veggie setup. In space it's not a good idea to waste anything, so the colors that give the most plant growth bang for a solar energy buck have been selected. Although some green has been added to the mix for the comfort of the astronaut gardeners.

Growing food in space is important if you intend to travel to Mars and beyond. So this is a historic first step in that direction. A baby step that is, because as you can see in the video this amount of salad could have made one meal for the crew, but not much more. To contribute significantly to the menu, a lot more needs to be grown, faster, and a lot of different things as well (like rice and beans for protein).

Nasa adds, by the way, that gardening could be good for the psychological well-being of astronauts on long journeys. Perhaps, but if they're going to take that seriously maybe they should simulate some sunlight, and grow some flowers too.

About Herbert Blankesteijn

Herbert Blankesteijn is a technology journalist from the Netherlands who has written for many prominent Dutch newspapers. He presented and directed television and radio programmes and has 10 books to his name. Herbert is interested in nascent fields such as 3D printing, drones, robotics and the private space business.