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The Perfect Astronaut Meal Might Be a Vegan Salad

Person in spacesuit near red rocks.
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The perfect meal for astronauts on long journeys may be a sweet potato salad, according to a new paper published in ACS Food Science & Technology.

The researchers behind the study evaluated the space-suitability of 10 dishes based on their nutritional content and whether the ingredients could be grown in space.

They concluded that a “space salad” consisting of soybeans, poppy seeds, kale, peanuts and sweet potato may be the ideal meal for long-distance space travel.

Salad bowl for Major Tom

The future of space travel is set for Mars. But any cosmonauts traveling that distance will need more than a few tubes of astronaut food for the whole journey; they’ll need substantial, nutritional cuisine that could be grown in-flight using recycled water.

To identify such a worthy meal, an international team of researchers considered 10 candidate dishes comprised of several of the same ingredients, such as kale, chard, spinach and animal products such as beef, trout and clams. Meals were first judged on their nutritional content.

“Nutritional requirements of astronauts are different from those on Earth because of the stresses placed on the human body under space conditions,” said Alex Burgess, an assistant professor of agriculture at the University of Nottingham told Technology Networks. “This leads to a larger calorie requirement and larger quantities of certain micronutrients.”

To guarantee a high dose of these vital micronutrients (such as magnesium, calcium and potassium), Burgess and her colleagues used computational linear programming to assess how well each of the 10 dishes met the nutritional requirements of a male astronaut while also being light and requiring precious little fertilizer, water and space to grow.

The model narrowed the options down to one dish: a vegan salad made up of soybeans, poppy seeds, barley, kale, peanuts, sweet potato and sunflower seeds. The meal doesn’t quite hit every nutritional benchmark, but any missing minerals could be provided with supplements, says Burgess.

Image credit: A space salad, adapted from ACS Food Science & Technology 2023.

“Long-term space missions will require approximately one ton of food per astronaut per year (considering a three-year Mars mission), most of which must be grown in situ to limit payload requirements, and which cannot be provided via automated supply missions, which occur every two months to the ISS,” Burgess explained.

“A space farming system must therefore be developed to supply this diet in a sustainable fashion. Our study provides the first stage towards designing the kind of system required in space by indicating a combination of crop species [that] maximize as much of the dietary requirement as possible. Some of the micronutrient needs are not fully met by this diet but provide a target for either biofortification approaches or for supplementation.”

The missing micronutrients didn’t rob the salad of its flavor, however.

In the last part of their experiment, Burgess and her colleagues put their calculations into practice and made a non-vegan version of their space salad (using chicken stock) for four volunteers to try. It received a mixed reception. One volunteer said the dish was “very sweet.” Another agreed, saying they “enjoyed the sweet taste of the potatoes and freshness crunch” but the “barley was a bit dry and could have been soaked longer.” One volunteer said they didn’t like the meal at first, while another enthusiastically stated they “wouldn’t mind eating this all week as an astronaut.”

Burgess and her colleagues say this taste test confirmed the salad’s palatability and highlighted areas where it could be improved during future research – research that will also, they say, include specific dietary considerations for female astronauts.

Alex Burgess was speaking to Leo Bear-McGuinness, a Science Writer and Editor for Technology Networks.


Reference: Liang S, Rivera-Osorio K, Burgess AJ, Kumssa DB, Escribà-Gelonch M, Fisk I, Knowling M, Stekel D, Hessel V. Modeling of Space Crop-Based Dishes for Optimal Nutrient Delivery to Astronauts and Beyond on Earth. ACS Fo. Sci. & Tech. 2023. doi: https://pubs.acs.org/doi/full/10.1021/acsfoodscitech.3c00396