How will we grow food in space?
The SHINE team this year entered the project with a wide variety of scientific interests. We were all adamant that we wanted to do something useful that would help NASA and other space organisations take a step towards sustainable space travel, and, possibly, space inhabitation.
There was much brainstorming, and we all suggested a range of incredible ideas. However, after a lot of deliberation, we decided to focus on plant growth, as we knew that food was essential for living conditions. Our initial plan was to create a self-sustaining biome by also including an element that could eat oxygen and produce carbon dioxide for the plants to consume. We were going to do this by including yeast in the experiment.
We encountered a few problems with the yeast and the plants interacting in such a close space with some of their excess products of respiration resulting in killing one another. As we were unable to overcome these issues within the time frame we had planned, the team decided to just focus on growing a plant, specifically chia, and obtain as much data as possible from the experiment.
Our experiment is based off the idea of chia pets, in which chia seeds are grown out of the head of a figurine in order to have it grow ‘hair’. We wanted to monitor the effects a growth solution hormone combined with plant food could have on the growth of the chia in microgravity when compared to on Earth. In order to ensure the chia plant could be able to grow, we also determined that the chia would get the right amount of gas exchange needed for growth, as small amounts of air could filter through the pores of the 3D printed chamber.
Our chia were embedded in cotton using water soluble glue from glue sticks and covered with a thin layer of tissue to help keep them from floating around the chamber when they entered microgravity. Once the experiment is on the space station, the seeds will be activated with by pumping five millilitres of diluted solution into the cotton pad.
The water has been dyed to contrast against the inside of the chamber so that we can see if any water escapes from the cotton. After that, two millilitres of water will be delivered to the cotton pad every two days. The Sproutstranauts have included a grid overlaying a picture of our team mascot, Groot, to measure the growth of the chia, which will be monitored with an hourly photograph.
We have also included humidity sensors to test the amount of water that enters the air in order to gage a better understanding of what the environment is like within the microlab. The Sproutsranauts included a day/night cycle for the plants by having lights activated for ten hours and lights turned off for twelve hours in order to ensure that the plant has a chance to undergo all of its natural functions. We have also conducted a control experiment on Earth to compare results to.