Shoot(s) for the Moon!

Using robotics to grow and harvest plants without human intervention? That’s the aim of GrowBotHub, an EPFL project under the auspices of the IGLUNA 2020 initiative, in which teams of students work together on technologies that can be used to design a space habitat. Final projects will be presented online in July.
© 2020 EPFL/GrowBotHub

There are many ways to express improbability, such as “when pigs fly” or “when hell freezes over.” How about “when vegetables grow on the Moon”? Actually, that might just happen, if the GrowBotHub team has its way. This interdisciplinary student project is part of the IGLUNA 2020 initiative, launched by EPFL’s Swiss Space Center on the initiative of the European Space Agency (ESA). The goal of IGLUNA is to determine what technologies astronauts need to survive on a mission to the Moon (or to other planets).

This is the second year of the IGLUNA campaign, and the project presentations – originally slated to take place in Lucerne on 10–19 July – will instead be held online. This year’s theme is remote control. The campaign brings together over a dozen teams made up of some 130 students from universities in ten European countries. Each team is focusing on an innovative solution for sustaining life in extreme environments, in areas such as water and food management, housing design and construction, communication and navigation systems, energy production, making and repairing tools, and human health and well-being. The previous year’s edition was held inside the Matterhorn glacier in Zermatt.

GrowBotHub, which recently became an EPFL-accredited association, is the school’s sole contribution to IGLUNA 2020. There are some thirty student members, most of them in Master’s programs. The team is pooling their knowledge from a variety of disciplines – such as robotics, chemistry, life sciences, data management, communication systems, microengineering, materials science and electrical engineering – to create an aeroponics system to grow and harvest vegetables without human intervention.

Aeroponics does not require soil. Instead, the plants’ roots are regularly sprayed with nutrient solutions. GrowBotHub’s robotic system intelligently calculates the variables based on each plant’s needs, including the composition and quantities of nutrients, pH, humidity, light and ambient temperature.

Spinach, radishes and chili peppers

In environments where resources are extremely scarce, the challenge is how to utilize and recover them as efficiently as possible. A vertical carousel system makes optimal use of available space and produces a maximum number of vegetables. To date, GrowBotHub has successfully produced green lettuce and spinach, as well as radishes, arugula and basil. Since lengthy stays in space tend to alter and diminish one’s sense of taste, the team is also looking at how to grow more pungent plants, like chili peppers, and whether it’s possible to cultivate root vegetables such as potatoes.

“The idea is for the system to meet 25% to 30% of astronauts’ nutritional requirements, and to harvest food at least once a day,” says Victoria Letertre, a systems engineer who’s also the president of the GrowBotHub student association. “The two months of lockdown – during which we had no access to either the campus or the robot – were an excellent test. We were worried about our project remaining viable, but in the end, the plants held up well and even continued to grow, which shows that the system really works.”

GrowBotHub has uses beyond the field of aerospace. It could also be deployed for polar expeditions or underwater exploration. Moreover, it has implications for sustainable living, with potential for small-scale, local, autonomous vegetable production.