The radish, turnip, and oregano seeds sit nestled in dark soil. Their cells pull oxygen from tiny pockets of air in the dirt around them – Martian air. The scientists watch camera footage of the soil from afar, waiting for the first earthly plant to sprout, breaking the ground of an extraterrestrial world.
What sounds like a science fiction film is actually an experiment being conducted by three Eastern Mennonite University (EMU) students. Laura Troyer, Jonas Beachy, and Andrew Schunn, with Professor Stefano Colafranceschi, built a capsule – sort of like a tiny greenhouse – that contains both regular soil and a soil mixture based on that found on Mars. Into the sealed chamber, they pump a blend of gases that mimics the atmosphere of Mars: 96% carbon dioxide and a smattering of nitrogen, oxygen, and argon.
Their hope is to prove that plants could, theoretically, be grown on Mars.
“We started with an idea and a bag of iron oxide, and with a little help from Stefano and a couple of biology and chemistry professors, created a fully autonomous Martian capsule that runs over the internet!” said Beachy.
He said that one of the most difficult parts of building the capsule was engineering the software that would measure the temperature and regulate the water and carbon dioxide in the capsule, as well as regularly photograph the soil surface and upload those photos to the internet.
“The RaspberryPi, or mini computers, we use run on Linux, which is a much different operating system than Windows 10 or Mac OS. Linux gives the user much more freedom at the cost of a simple experience for the user,” Beachy explained. Luckily, “Stefano is well versed in Linux and was always willing to help us figure out the issue.”
“As learning any coding language, it just takes time and lots of time in the lab until we got it working,” added Troyer. “We spent a lot of late nights in the lab working on the programming pieces – bouncing ideas off each other and chiming in with ideas when we got stuck.”
“Running an experiment is always a rewarding experience,” Colafranceschi said. “It’s a way to talk to nature and decrypt the answer.”
The experiment was informed by NASA research that indicated Martian soil has the necessary nutrients for plants to grow. But, of course, there are other considerations – Earth’s atmosphere is approximately 100 times denser than that of Mars, but the trio found that its high concentration of carbon dioxide should compensate for that.
Then, there’s sunlight to think about. “According to sunlight intensity measurements, the intensity of light is on average less than Earth, but similar to sunlight intensity around the 40th parallel over the winter months, and enough light for almost all plants,” the team wrote.
Next, temperature: the average temperature on Earth is 57 degrees Fahrenheit, whereas on Mars, it’s 81 below zero, so the experiment assumes you’d be farming inside a greenhouse on the red planet.
So far, they haven’t had any Martian veggies sprout. But the young scientists take pride in the fact that they did, in fact, build a Mars capsule.
“The most rewarding thing about the project was the last few weeks seeing everything come together,” Troyer said. “Once we got the box put together and the soil mixed, we were at the point where we were putting the finishing touches on a lot of the coding pieces. It was exciting to see it all come together and to see that what we designed actually worked.”