Abstract

The Deep Space Food Challenge is an open competition to drive the creation of food production technologies to provide “safe, nutritious, and tasty food” for long-duration flights. The winners relied on slever design and engineering to create palatable and shelf-stable meals.

Article

Astronaut Kjell Lindgren juggles a supply of fresh fruit that arrived on a supply ship. Most food on the International Space Station is shelf-stable and highly processed. Photo: NASA

Astronaut Kjell Lindgren juggles a supply of fresh fruit that arrived on a supply ship. Most food on the International Space Station is shelf-stable and highly processed. Photo: NASA

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Kjell Lindgren, a medical doctor and astronaut who has spent a cumulative total of 311 days in space aboard the International Space Station, knows a thing or two about how to— and how not to—prepare food in space. Hot meals are particularly tricky.

Currently, space station residents prepare food using a food warmer, which Lindgren described as “essentially a hot plate,” to heat up thermostabilized items in metallic envelopes. They can also add water to dehydrated options onboard. Think of how backpackers reconstitute foil pouches of dried spaghetti and sauce.

Lindgren recounted how a fellow crew member accidentally left a valve open in a dehydrated food package after adding water.

“It was pea soup. And this person, who will remain nameless, started swinging the bag around in an arc to try to get the water down into the soup mix using centrifugal force,” he said. “Unfortunately, a valve was open, and the soup escaped. You could track exactly where his arm had gone because there was this circular mist of pea soup. We found pea soup stains all over the place even weeks later.”

When space agencies such as the National Aeronautics and Space Agency (NASA) and the Canadian Space Agency (CSA) make plans to send a manned mission the 200-plus million miles to Mars in the 2030s, they aren’t envisioning the latter-day Neil Armstrong with a dollop of soup on his forehead. But they will need to find ways to successfully fuel the crew.

Space food during the first decades of crewed missions had a justifiably bad reputation, since the prized attributes were weight, shelf-stability, and nutritional density, not taste or mouthfeel. That filtered down to the popular culture: Companies sold freeze-dried nodules as “astronaut ice cream” that were more of a novelty than a dessert. “Astronaut orange juice” was, famously, Tang.

“Food determines how far from Earth you can go and how long you can stay,” said Michael Dixon, who leads the Space and Advanced Life Agriculture (SALSA) program at Canada’s University of Guelph. “For this kind of human space exploration to happen, we need to find ways to provide adequate nutrition to the people onboard while they are traveling. We also need to figure out how to grow food in harsh and extreme environments once they get there.”

To achieve those goals, NASA and CSA rolled out the Deep Space Food Challenge (DSFC) in 2021, an open competition to drive the creation of food production technologies to provide “safe, nutritious, and tasty food” for longduration missions to the moon—and beyond. The winners are expected to be announced next year.

The SATED system can safely cook a variety of foods in microgravity, including a pizza made from Bisquick, water, pepperoni, tomato sauce, and cheese. Photo: Sated

The SATED system can safely cook a variety of foods in microgravity, including a pizza made from Bisquick, water, pepperoni, tomato sauce, and cheese. Photo: Sated

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“Some of NASA’s hardest challenges, historically, have been solved by regular people,” said Denise Morris, deputy program manager of the contest. “There are a lot of smart people out there—and they may have out-of-the-box ideas about how to provide nutritious food that crew members will actually want to eat. Because that may be the biggest challenge involved here—if the food produced isn’t tasty, no one is going to want to eat it.”

READY TO EAT

Crew members aboard the International Space Station live off pre-prepared, pre-packaged items, Lindgren said— and lots and lots of Sriracha.

“NASA’s Food Lab has worked hard to create a diverse menu that included things like fajita chicken and beef stew. But, over the course of six months, it becomes repetitive. Which is why I started mixing things up and added hot sauce to just about everything I ate,” he said.

Lindgren added that astronauts have a special way of eating their pre-packaged food offerings to manage the lack of gravity. Not doing so can not only lead to missing out on important calories—it can also lead to debris with the potential to interfere with onboard systems.

“We use scissors to cut open the envelope the food is in and a spoon to get it out—and you have to make sure to be deliberate, smooth, and slow as you eat because only surface tension is keeping the food on the utensil,” he said. “If you go too fast, you can make a real mess.”

Lindgren was also a member of the first crew to successfully grow—and eat—crops in space, working against such factors as limited light, scarce water, cramped quarters, and weightlessness. He said such systems were fine for a demonstration, but aren’t scalable for long haul space travel.

“We used these little soil pillow matrices—it basically looked like a bean bag with a nozzle on it,” he said. “We would deliver water and nutrients into the bag and, once the seed germinated, would introduce the roots into the soil so the plant could grow outward. It’s a cool system but it’s dirty—and it requires too much volume and mass for too little of a harvest. It wouldn’t work for a long duration mission.”

That’s why the Deep Space Food Challenge was needed to spur innovators to come up with new ideas, Morris said— especially new technologies that provide “maximum output from minimal input.”

“The goal is to cut back on the necessary resources that we have to carry with us,” she said. “You have limited space to work with and need to find ways to minimize waste. And you need any systems used, whether onboard or on the surface, to be safe. They have to work in extreme environmental conditions, not cause any kind of fire or hazard, and the food they produce can’t make the crew sick.”

The Air Company’s system feeds synthesized alcohol to yeast to produce edible proteins. Photo: Air Company

The Air Company’s system feeds synthesized alcohol to yeast to produce edible proteins. Photo: Air Company

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The Mu Mycology closed loop fungal cultivation system is designed to produce a sustainable harvest of mushrooms. Photo: Mu Mycology

The Mu Mycology closed loop fungal cultivation system is designed to produce a sustainable harvest of mushrooms. Photo: Mu Mycology

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The DSFC has an additional requirement for competitors: The food systems they create should also have applications to help provide sustenance for people living in harsh environments here on Earth.

“This goes beyond the technical challenges of going to the moon or Mars,” Dixon said. “These kinds of solutions could help us grow food year-round in areas like Northern Canada or the deserts of the Middle East—and deliver both food and life support to people who need it.”

ORBITAL ENTREES

More than 300 teams representing more than 30 countries submitted designs to the DSFC. In the competition’s first phase, NASA culled the list to 18 promising American groups—and those teams were awarded $25,000 to build small-scale prototypes of their systems. (A separate track of 10 international winners recognized teams from Colombia, Finland, and Saudi Arabia.) Those designs were showcased at the NYCxDESIGN Festival in New York in May 2023. They included a wide range of offerings that could have been manifested straight from a science fiction movie, including novel hydroponic garden systems, a 3-D-printing-esque food extrusion system, and a controlled plant growth chamber to support high-density crop production.

Mahlet Garedew, lab manager at Air Company, a Brooklyn-based startup that made the cut, displayed a carbon conversion technology that imitates photosyn-thesis—ultimately producing an edible protein powder that can supplement crew member rations.

“We split water to produce hydrogen gas and oxygen through on-site electrolysis. The hydrogen from the water electrolyzer is then combined with carbon dioxide over proprietary catalysts to produce ethanol, methanol, paraffins, and water,” Garedew said. “The mixture of alcohols and water can then be used to feed microbes in the next step of the process, where ethanol is diluted to an ideal concentration and then combined with a nitrogen source and other nutrients in a fermentation flask. Yeast then gets added to the mix, which utilizes the alcohol from the carbon dioxide to grow and produce single cell proteins which can be extracted and dried into an edible powder.”

Another contender, Hillsboro, Ore.-based Mu Mycology, developed a closed-loop fungal cultivation system. Nicolaas Vermeulen, one of the team members, said they leveraged existing technologies to monitor and control temperature, oxygen, carbon dioxide, light, and humidity, and created a unique liquid nutrient delivery system that enabled them to produce mushroom fruiting bodies again and again with little to no waste.

“By creating this kind of contained system, we can decrease the footprint while continuously producing mushrooms without waste production,” Vermeulen said. “It has a 3-D printed scaffold, and we put a sort of substrate for the mycelium to grow inside of it. We feed the mushrooms through a nanopore drip system, induce fruiting, harvest, and then re-feed them so they’ll recolonize and fruit again. We can get a harvest every two to three weeks that provides a meal for two to four people.”

Other groups took on the challenge of food prep. To replace the space “hot plate,” the Safe Appliance, Tidy, Efficient, and Delicious (SATED) team from Boulder, Colo., created a galley cooking appliance that can be used in-flight. The device can safely cook a variety of foods in microgravity, including a pizza made from Bisquick, water, pepperoni, tomato sauce, and cheese.

“NASA has basically been doing the same thing for the past 20 years when it comes to food. This device makes it possible to go to space and make good food—and allows astronauts to do it without the danger of smoke or fire,” said Jim Sears, team lead for SATED. “We use positive temperature coefficient heaters, which are about the size of a domino. They heat up like any resistor when you put a current through them. But they only get to about 400 and some degrees Fahrenheit so there’s no risk of fire. The appliance also has a downdraft table that pulls in the air above it through a filter cloth, which allows you to keep both hands free to cook and eat and not worry about losing ingredients or food.”

Morris said the crowd was excited about the different options—and she and others tried a lot of good food including mushroom jerky and chocolate pudding that were produced by the prototype systems.

“The different designs were just so creative,” she said. “But more important, the teams had some very tasty and nutritious food to serve.”

KITCHEN DEMONSTRATIONS

After the demonstration at NYCxDESIGN, each submission prototype was evaluated by a panel of judges, recruited from NASA, academia, and industry. The judges assessed each idea based on the design innovation as well as the team’s scientific and technical approach. But they also kept an eye toward feasibility—could the system really work inflight or after landing on the moon or Mars? Would it have terrestrial impact for areas that have trouble cultivating their own food?

An LED-based vertical farming demonstrator at the University of Guelph may be adapted for growing food on long-duration space missions. Photo: University of Guelph

An LED-based vertical farming demonstrator at the University of Guelph may be adapted for growing food on long-duration space missions. Photo: University of Guelph

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Team members from Interstellar Lab prepare samples to share at the Deep Space Food Challenge event in Brooklyn in May 2023. Photo: Jonathan Deal

Team members from Interstellar Lab prepare samples to share at the Deep Space Food Challenge event in Brooklyn in May 2023. Photo: Jonathan Deal

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“After this kitchen demonstration phase, we selected eight finalists, including five U.S. teams, to continue on to the next phase of the challenge,” said Morris. “It will involve a full demonstration of their systems, in a place where it can be set up for astronauts to use without much input or any interaction from the designers.”

NASA expects this final phase will take place next year. In the meantime, the American phase two winners, which include Air Company and SATED, are already thinking about how to use the $150,000 prize money to improve their systems. For her part, Garedew said her team is “ecstatic” to move on to the final phase of the DSFC.

“We’ve worked hard to bring this technology to life and showcase this application for our carbon conversation technology,” she said. “Participating in this challenge has allowed us to expand the way we see the potential applications of our technology—and we’ll be working toward the phase three requirements and planning our next steps to develop this technology further to be suitable for application in space.”

Sears is already thinking about how to make improvements to the SATED design—and how to make it even easier for tomorrow’s astronauts to cook in space. One of the next steps is building a new prototype four times the size of the current appliance using only twice as many heaters.

“As an engineer, I see problems as fun and there is some terrific engineering we can do now,” he said. “Until now, I’ve built and machined everything in my own shop. But now I have a mechanical engineer working with me. I want to make my thermal margins a little skinnier and am looking at using Teflon non-stick material rather than silicone. Winning this phase gives us the opportunity to do all kinds of cool engineering things to make SATED even better.”

Lindgren, for his part, is excited to see what the next phase of the DSFC brings. He said his imagination conjures a greenhouse module that will not only consistently produce crops but provides a sanctuary where astronauts can float in a place surrounded by fresh, green plants. But he is open to any feasible system that will help to sustain and nourish a crew during a future Mars mission, while cutting down on pea soup mishaps.

“Food is a fundamental part of being human,” he said. “It’s not just important for our nutrition and preserving our bone health, muscle health, cognitive health, and cardiovascular fitness in space. There’s an important psychological aspect to it, too. As humans, we use food to celebrate. We use food to commiserate. We used food to gather and to bond. Food plays that same role in space—and anything we can do to support that while supporting the nutritional needs of our crew on these future missions will be of benefit.”