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Researchers design a ‘space salad’ to keep astronauts healthy and happy

When it comes to imagining food in space, the first thing that’s likely to cross most people’s minds is freeze-dried products like astronaut ice cream. And while preserved foods will inevitably be a part of astronaut’s diets for the foreseeable future, nowadays there’s an increasing focus on how to provide astronauts with fresh foods like vegetables and grains for at least occasional treats.

Eating fresh foods is important not only for physical health reasons, but also for astronauts’ mental health. Repetitive, processed meals can be unappetizing and lead to what is called menu fatigue, in which astronauts don’t want to eat because they are so sick of having the same foods over and over. And that can be a real problem when astronauts are losing weight and not getting enough nutrients.

Fortunately, we’re getting better and better at growing a wider variety of foods in the microgravity conditions of space. In the last few years, astronauts on the International Space Station (ISS) have grown foods like radishes, lettuce, and chili peppers. And now, a team of researchers has come up with an “astronaut salad” featuring foods that could be grown in space.

A salad created to provide nutrition for astronauts based on foods which can be grown in space.
A salad created to provide nutrition for astronauts is based on foods that can be grown in space. University of Adelaide

The salad, developed by researchers at the University of Adelaide in Australia and the University of Nottingham in the U.K. contains a mixture of the following: soybean, poppy, barley, kale, peanuts, sweet potato, and sunflower seeds. The precise amounts of each ingredient have been adjusted so that it delivers the nutrients an astronaut would require as measured by a 2011 NASA study, — and so that it tastes good as well.

“We have simulated a mix of six to eight crops that deliver all the required nutrients that an astronaut needs, which is different from what people need on Earth,” one of the researchers, Volker Hessel of the University of Adelaide, said in a statement. “While there are dozens of crops that can fulfill an astronaut’s nutrient requirements, we needed to find those that could pack a punch and deliver the calories needed in smaller portions that could be grown in a small space.”

The researchers used a computational model to help them balance the nutritional needs of the astronauts, working from a list of more than 100 plants that could be suitable for growing in space. These are foods that can be grown in a small space, in a hydroponic system, and require minimal fertilizer.

To keep the meal appealing, the researchers chose plants with a variety of colors, textures, and flavors. “Food is such an integral part of staying healthy and happy, and there are many factors that contribute to this,” said another of the researchers, Shu Liang of the University of Nottingham. “As well as the nutritional values and ability to grow the plants in space, we also looked at other important aspects of a space diet to promote astronaut well-being, including color, taste and eating together.”

A team of volunteers tasted the salad and seemed happy with it, with one saying that they “wouldn’t mind eating this all week as an astronaut.”

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