ISS to ISF: how researchers are developing new growing technologies for zero gravity

A team of researchers from the University of Sheffield’s Institute for Sustainable Food has developed a new hydroponic cabinet that uses a polymer foam to grow plants.

The cabinets, which are built by Grobotic Systems, are of the same dimensions as the Advanced Plant Habitat (APH) on the International Space Station to use as outreach showpieces.

With the support of the University’s pump priming grants, the SpaCEA team were able to build two cabinets that were displayed during the Pop-up University earlier this year. 

A Raspberry Pi, a small customisable computer, is built into the cabinets to monitor when the plants need water and measure light, temperature and humidity levels. A camera also takes images to monitor plant growth remotely.

The plants grow in a polymer foam developed at the University for use in high-value hydroponics as an alternative to Arcillite, an expanded clay material that NASA currently uses to grow plants in. 

The new foam is much lighter than Arcillite and so three to four times more can be sent up into space using the same amount of fuel. This would allow astronauts to grow more food and could help sustain longer missions. 

The team hopes to use this foam to develop a growing system compatible with the APH growth facility used by NASA.

Growing food in space requires the reuse and recycling of all raw resources as resupply missions are impractical and unsustainable. Using space as a pilot for testing circular systems later used on Earth could help break the linear supply chains currently used to produce our food. 

Dr Harry Wright, from the University's Department of Chemistry, “This research is on the cutting edge of plant growth technology however running this alongside a citizen science project brings the project right down to earth (excuse the pun) affording anyone the opportunity to add to the research and learn about growing food both on earth and in space.”

Luke Fountain, a PhD researcher at the University School of Biosciences, said, “The SpaCEA project has given us the opportunity to highlight both to researchers and, perhaps more importantly, the general public, the importance of growing plants in space. 

“This field is becoming increasingly important in human space exploration but it is also crucial to help us tackle food insecurity on Earth, and to us considering both challenges together can help us to make real advances in improving food security on Earth and beyond."

The next step will be to set up a longer experiment, growing chilli peppers from seed through to collecting fruit, which will take around 3 months, testing the performance of the cabinets over a longer growth cycle in addition to testing germination and early seedling growth in the foam. 

A second cabinet will include NASA's arcillite substrate instead of the foam, allowing the team to also compare the two substrates, demonstrating the potential of PU foam as a substrate for space plant growth.

The team also hopes to start a citizen science project where members of the public are asked to grow herbs and leafy greens in small blocks of foam.

To keep up with the SpaCEA team’s progress, follow them on Facebook, Twitter and Instagram.

Listen to the SpaCEA team's podcast episode

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