The Orbital ATK CRS-9 resupply mission to the International Space Station will carry 25 student-designed experiments. One of them envisions a future that includes sustainable farming in space!
Meet the Saguaro Snakes. This is a team of five high school students in Gilbert, Arizona, who won the Orbital ATK Division of the Go for Launch! competition in 2017. Go For Launch! is a multi-day program run by Higher Orbits that introduces students to astronauts and other spaceflight experts, engages them in collaborative activities, and culminates in a challenge to design a space experiment.
The Saguaro Snakes’ winning experiment is Biological Nitrogen Fixation via Rhizobium-Legume Symbiosis. That name may look bewildering, but some quick background will help it make sense. Nitrogen is essential for life. It’s in proteins, DNA, and ATP, the molecule that allows living things to extract energy from food. In plants, it’s also in chlorophyll, the green pigment that makes photosynthesis possible. Plants need plenty of nitrogen. Air is mostly nitrogen gas, but plants can’t extract nitrogen directly from the air. They need nitrogen in a form that is compatible with the chemical processes in their cells. They need “combined” or “fixed” nitrogen.
A soil deficient in fixed nitrogen cannot support healthy plants. One way to add fixed nitrogen is to use a synthetic fertilizer made with ammonia. Large-scale farms use millions of tons of such fertilizer each year. But manufacturing nitrogen fertilizer uses hazardous, potentially explosive ingredients, and overusing nitrogen fertilizers leads to air and water pollution. It would be risky to rely on synthetic fertilizer in an isolated, delicate system like a spacecraft or a Mars colony.
Instead, our future space farmers will need a natural solution for enriching soil: biological nitrogen fixation. The nitrogen “fixers” are bacteria living in nodules, or bulges, on the roots of certain plants. A common type is Rhizobium, a species that colonizes legume plants such as peanuts and clover. The host plant’s roots absorb the nitrogen, while the bacteria eat food produced by the plant. This mutually beneficial relationship is called symbiosis. That’s the breakdown of the experiment’s name.
In other words, these high schoolers are studying a natural process for maintaining healthy soil that could help us grow crops on spacecraft and on Mars!
This is the second incarnation of the Saguaro Snakes’ experiment. The first version launched on the OA-8 mission in November 2017, but to the students’ and mentors’ surprise, their legume plant’s seeds failed to sprout. Higher Orbits and its hardware partner Space Tango made it possible for the team to rebuild and re-fly the experiment on OA-9.
Two Saguaro Snakes team members, Nicolas and Abi, discuss the project in their own words.
What is your experiment?
NICOLAS: Our project focuses on whether zero gravity would affect how much nitrogen is produced by a plant called microclover. Most plants take nitrogen from the soil, but microclover actually puts it back into the soil, which could be used to improve soil composition on Mars, and hopefully lead to the colonization of Mars.
How did you choose this topic for an experiment?
NICOLAS: Abi has taken agriculture classes and brought up the idea. After trying to come up with something for two days, that was the best idea we had.
ABI: With the help of our STEM teacher and the 2015 movie The Martian, we came up with the idea of plant growth in space.
What has been especially fun about working on the project?
NICOLAS: The coolest part for me was how a small idea that we had over a weekend grew into an actual experiment on the ISS. It still is astonishing to me.
ABI: When I was little I would go out to my yard, lay down, and just stare at the stars. My mom would come out in the morning in a panic and see that I feel asleep looking at the sky. I never once thought I would design something that would be sent up there. And now that I have, it feels like a dream come true.
What’s something you’ve learned from this experience?
NICOLAS: I’ve learned the importance of communication on completing this kind of project. I’ve always done school projects on my own, but from this I learned that the rest of the world works together, and so I learned how to effectively communicate with my peers as well as superiors.
ABI: Not only did my team win and do something incredible, but we also showed that girls can do this too. It’s not just “a man’s job” and just because you’re a girl in a business full of guys, doesn’t mean you can’t do it. You just prove to all of them that you can.
Has this experience affected your thoughts about the directions you want to take in school or a career?
NICOLAS: My decision to study physics in college was mostly made because of this experiment. I want to continue working in space, and becoming an astrophysicist would be a great way for me to do it.
ABI: I want to become an aerospace engineer.