From Algae to Lettuce, Agriculture

as Already Shown Promise Out of Orbit.

NICOLA TWILLEY CYNTHIA GRABER and GASTROPOD

April 28, 2019

Today, a half century after Neil Armstrong took one small step onto the surface of the moon, there are just three humans living in space: the crew of the International Space Station. But after decades of talk, government agencies and entrepreneurs are now drawing up more concrete plans to return to the moon, and even travel onward to Mars. Getting there is one thing, but if we plan to set up colonies, we’ll have to figure out how to feed ourselves. Will Earth crops grow in space—and, if so, will they taste different? Will we be sipping spirulina smoothies and crunching on chlorella cookies, as scientists imagined in the 1960s, or preparing potatoes 6,000 different ways, like Matt Damon in The Martian? Listen in this episode for the stories about how and what we might be farming once we get to Mars.

Space is harsh. We aren’t suited to the thinner atmospheres and lower gravitational pull of Mars or the moon, and without Earth’s atmosphere to protect us, cosmic rays could damage the structure of our cells, including our DNA. Plants, it seems, are a little tougher than humans when it comes to adapting to the rigors of alien worlds: According to the NASA scientist Ray Wheeler, scientists began sending algae into space in the 1950s, and since 2015, U.S. astronauts on the ISS have been able to enjoy the odd leaf of homegrown lettuce, thanks to the work of Wheeler’s Kennedy Space Center colleague Gioia Massa.

Read: How do plants grow in space? 

One of the big leaps forward in space agriculture came little more than a decade ago with the introduction of broad-spectrum, affordable LED lights—these are now powerful, efficient, and cool enough to allow plants to be grown entirely indoors. In this episode, Gastropod visits Wageningen University in the Netherlands, the world leader in indoor farming, where the scientist Esther Meinen drew on her greenhouse expertise to select the crops and design the best “light recipe” for EDEN ISS, a European space-farming prototype that provided fresh herbs and vegetables to the crew of the Neumayer Antarctic station throughout the last polar winter.

Those radishes, celery, and tomatoes were all grown hydroponically, without soil. But plants love soil—and on Mars, the subsurface soil may even offer some water. So can we grow crops directly in Martian or moon dirt? As it turns out, although Apollo astronauts brought nearly a thousand pounds of rocky dust back from the surface of the moon, no one at NASA had ever used it to grow plants. The remaining lunar material is too precious for NASA to hand out, and we don’t even have soil from Mars. But a few years ago, Meinen’s colleague Wieger Wamelink decided to try growing plants using Martian- and lunar-soil simulants. In this episode, we visit his Martian test plot to learn about the challenges of exoplanetary terroir—and taste the results. And whether we get there or not, it turns out that figuring out how to grow plants in space has plenty to teach us about farming here on Earth. 

Listen in this episode for the how, what, and why of space agriculture.