The space salad contains ingredients — including soybean, poppy, barley, kale, peanuts, sweet potato and sunflower seeds — that could be grown on spacecraft and provide optimum nutrition for astronauts.
“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,” said Professor Volker Hessel, research director of the Andy Thomas Centre for Space Resources at the University of Adelaide.
“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.”
Professor Hessel and colleagues used daily dietary requirements for astronauts suggested in a 2011 study by NASA scientists.
They created a computational model to predict the best combination of plants for a ‘space salad’ and considered more than hundred different plants.
They selected plants that could provide an astronaut with a nutritionally complete and calorically balanced plant-based diet, and included no more food mass than people commonly eat on Earth.
To make the cut plants needed to meet other strict criteria to be part of the space salad.
The choice of plants had to be restricted to less than ten different varieties for simplicity purposes.
Plants must be grown in situ using space farming systems like hydroponics and take up as little cultivated area as possible.
They also need to use as little fertilizer as possible to minimize payload.
The effect of food on the mood of the astronauts was also important to the project with color, taste, texture, freshness and flavor also considered.
“Food is such an integral part of staying healthy and happy and there are many factors that contribute to this,” said Dr. Shu Liang, a researcher at 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.”
The researchers aim to design space farming systems and components for long-term space missions to meet the nutritional and psychological demands of astronauts.
“Four volunteers tasted the space salad and one concluded that they wouldn’t mind eating this all week as an astronaut,” said Karolina Rivera-Osorio, a planetary research graduate from the City College of New York, who conducted a food psychology study called the Harmonic Psychology of a Space Salad.
“The next stage of the research will be using digital twin modeling to design the growth chambers and systems that can grow the crops.”
