If you needed to keep a space crew fed on their three-year round-trip mission to Mars, how would you pull it off without any resupply services?
The Canadian Space Agency issued that question as a challenge to intrepid inventors across the country, and 10 semi-finalists have been chosen to test their prototypes. The ideas represent a biodiverse range of solutions, including insect-based composting, algae bioreactors, modular crop pods, and even a fungus-based “space bacon.”
Until now, astronauts have brought all the food they need with them to space, or had supplies sent to them. But as missions get longer and further from home, astronauts will need to grow their own food. Food production needs to be safe and fill all their daily nutritional needs for months or years. Resources used to grow the food will also be limited, and ideally meals will be easy to prepare and enjoyable to eat.
All the semi-finalists now have funding to build their prototypes and will compete in a test kitchen this fall. Read on to learn more about their designs.
Breaking down organic waste for reuse is a key component of any long-term space mission. Maple Ridge, BC-based Canacompost Systems proposed the use of black soldier flies to assist in making high-quality compost.
Black soldier flies are produced in the compost chambers, and mature larvae self-harvest by migrating to a pupating chamber through internal tubing. From there, a fraction can be harvested for animal feed, and the rest of the pupae hatch as flies. The flies are guided through tubing to a specially lighted reproduction chamber to lay eggs to restart the life cycle.
Machine learning using sensor data can help astronauts adjust conditions or add more black soldier flies or other components to improve the resulting compost. The compost can be used both on board and to enrich poor extraterrestrial soil to boost crop production.
Students at McGill University’s McGill Advanced bio-Regenerative Toolkit for Long Excursion Trips (MARTLET) team netted two semi-finalist positions in the challenge. The first is a controlled habitat for raising edible crickets.
“MARTLET is very much a student-led initiative, and the student leaders of the two semifinalist teams are working hard to solve deep space’s challenges,” said supervisor Mark Lefsrud in a press release. “The students are not hindered by any preconceived ideas of how to do things.”
Starting with a few hundred eggs and only enough electricity to power a laundry dryer, the team anticipates that their device can produce tens of thousands of crickets every month. Compared to cattle, crickets take up a smaller footprint and are 12 times more efficient at converting feed into edible food. Harvested at just the right time, the unit can avoid the development of the indigestible exoskeleton to create a versatile and tasty protein-rich powder.
Algae are packed with nutrients, which explains why three of the semi-finalists chose them for their designs.
A second team of MARTLET students proposed to grow spirulina: a blue-green algae often sold in health food stores as a dietary supplement. They designed a cartridge-based photobioreactor to grow the algae, but the unit also includes in-house harvesting, dewatering, and processing to produce edible gels and drinks.
It doesn’t take much of the spirulina-based products to deliver a lot of nutritional benefit, making it easy to use flavour additives to customize the taste. The team collaborated with Ontario-based company FlavorCAN to combine their product with classic flavours to make it easy to eat regularly for years without getting sick of it. In particular, it can mimic the taste of fresh produce, which will be harder to come by in large quantities in space.
Richmond, BC-based AlgaBloom collaborated with the UBC Hallam lab to grow sustainable and nutrient-rich foods, also using spirulina as the base. Their bioreactor uses biofilm-based growth to get more product with less water.
The system transforms carbon dioxide from astronauts breathing, combining it with human waste to turn it back into a variety of edible foods. They can use the spirulina to make smoothies, yogurt-like pastes, chips, pastas and flakes.
Chemical engineers Valerie Ward and Nasser Abukhdeir from the University of Waterloo also plan to harness the power of microalgae with their rack system. Each day, all astronauts need to do to harvest the microalgae is squeegee off a layer, and they get a nutrient-dense ingredient that tastes like spinach. It grows enough to meet about 20 percent of the food needed to feed the crew.
Three more semi-finalists are designing mini greenhouses to efficiently grow fruits, vegetables, and fungi in space.
North Vancouver-based Ecoation is designing modular greenhouses to grow several efficient crops, including strawberries, cherry tomatoes, two root vegetables, microgreens, four unique culinary herbs, mini-head lettuce, an algae superfood, and a compressed meat substitute made from the filamentous mycelia of fungi that they call “space bacon.” Every year, the platform can yield 500 kg of food.
Graduate students from the University of Guelph are also building greenhouses. Their sealed growing environment can control elements like temperature, humidity, carbon dioxide concentration, and light intensity. The team has already shown that they can tune taste, growth, and nutritional quality by changing the colour of light used.
Port Hope Ontario-based PeaPod Technologies’ system grows crops by applying water and nutrients directly to a plant’s roots. The platform can be used to grow any crop, but miniature potatoes could contribute up to 2,000 calories a day for the crew’s meals. Machine learning can be used to optimize crop growth as the system learns more over time. There are automated controls on air thermoregulation, humidification, dehumidification, lighting, and aeroponics to get the best results.
Peterborough, Ontario-based Noblegen chose to grow Euglena-gracilis: a single-celled organism that evolved before plants and animals split into separate branches of the evolutionary tree. It’s a richer source of the nine essential amino acids than other non-animal proteins and also provides healthy omega-3 fatty acids. Euglena can photosynthesize, making it possible to grow them in photobioreactors for protein, crisps, and a scrambled egg substitute.
Lastly, a team from Concordia University aims to grow yeast in space, but they boosted their odds of it working by developing microgravity-tolerant yeast that they call AstroYeast. They used UV light to trigger random mutations and used microgravity simulations to select the best strains. Not only can the yeast be used as a nutrient-rich spread, the yeast could also be used to make medicines or bioplastics.
Food security in the harshest conditions also has benefits on Earth
While the primary goal of the challenge is to find food solutions for space travel, these compact solutions could improve food security on Earth. As we struggle to grow enough crops on limited land, these are welcome inventions.
From crowded cities to remote communities, they could provide fresh and local food options in the most extreme environments.