The ISS's latest harvest is a big step toward growing crops on Mars, and it smells a lot sweeter than Matt Damon's poop-fertilized potatoes in The Martian. After about three months of careful monitoring, International Space Station crew member Scott Kelly harvested a crop of flowering zinnias this Valentine's Day. The ISS zinnias, along with the control group grown on Earth at NASA's Kennedy Space Center, are part of the ongoing test of the Veggie plant growth equipment, which scientists hope to one day implement on deep space, Mars-bound missions.
Astronauts have successfully grown plants on the ISS before: Last August, crew members dined on "outredgeous" red romaine lettuce. This time, as far as we know, no one ate any zinnias. But while the flowers are less edible, growing them successfully on the ISS means humans are a lot closer to real, sustainable space agriculture than they were before.
“We wanted to test something that they wouldn’t eat, but would still enjoy," says NASA's Veggie science team leader Gioia Massa. "Something that was longer duration [than the 33 days it took to grow lettuce]. And we wanted to test out flowering, since flowering is much more complicated than just leaves.”
Growing food in space is already complicated enough. "Water and air don’t mix well in microgravity," says Massa. "And roots need water and oxygen."
The problem is that at zero g, water tends to float around in beads instead of going where scientists would like it. To combat this, Veggie equipment comes with ceramic tubes that bring the roots the moisture they need. Those roots are further nourished by controlled-release polymer-coated fertilizer brought from Earth (so in case you were still wondering, there is definitely no feces involved). The Veggie system is much more like a Chia pet than traditional farming.
The project did hit a few snags---mostly unexpected fungal growth---but overall it was a success. A big part of the zinnia project is validating the functionality of Veggie hardware and working out the kinks, and, even more importantly, our ability to grow more complex plants that will provide substantial and nutritious food for astronauts. Once the sample zinnias make their way Earthward, Massa and her team will look for signs of pollination and seed production, which will be key if humans want to really farm out in space.
"In a few years, we'll try tomatoes, and astronauts will have to hand pollinate the flowers with paint brushes," says Massa. "And we'll work on the ground to get the 'best recipe' ... for vegetables with the most nutrition, the most flavor."
Surviving in the vacuum of space is no easy task. But if humans are going to continue to explore, they'll have to learn how to do just that, and for long stretches of time. Hopefully, for astronauts' sake, the Veggie team's developments will make those journeys a little more palatable.
