Nasa
Researchers have evaluated 10 ‘space dishes’ on their suitability for multiyear space travel, and identified what might be the best of the bunch – a salad with ingredients that can be grown in space.
Among the many challenges involved with sending astronauts to Mars and beyond is what to feed them.
Space food should be lightweight, long-lasting, calorie-dense and nutritious. Astronauts in space burn more calories than their counterparts on Earth, and require additional micronutrients, such as calcium, to stay healthy in microgravity. Although the days of astronauts surviving on mysterious edible cubes and pastes squeezed from tubes have passed, space voyagers today still depend strongly on freeze-dried, prepackaged food.
The vitamins in this food break down over time. This is not a problem for astronauts on the International Space Station (ISS), which receives regular resupply shipments, but with Nasa and other space agencies proposing to send astronauts on much longer-term missions – it is unlikely that a round-trip to Mars could be completed within a year – space food will need reinventing.
Multiyear missions require food to be grown in a sustainable, circular way within a spacecraft or a space colony. Space agencies have already demonstrated that it is possible to grow plants under these unnatural conditions – Nasa’s ‘veggie’ space garden on the ISS has been used to grow lettuce, cabbage, mustard and kale, while Chinese astronauts have grown multiple harvests of vegetables in the Tiangong space station.
Despite this research, there had been no development of specific fresh meals for astronauts.
So Dr Volker Hessel and his colleagues at the University of Adelaide decided to find the best possible meals that can be grown in space, meet nutritional needs, and taste good.
They used a model to identify how well various combinations of foods could meet the daily nutritional needs of a male astronaut while minimising the water required to grow those foods. They also prioritised ingredients that needed minimal fertiliser, time and space to grow, and that produced minimal non-recyclable waste.
Of the 10 space meals they assessed (four vegetarian and six omnivorous), a vegetarian meal comprising soybeans, poppy seeds, barley, kale, peanuts, sweet potato and/or sunflower seeds provided the most nutritious meal while consuming the least resources. Although this combination does not provide all of the micronutrients a male astronaut would require, the missing micronutrients could be added in a supplement.
Hessel’s team then made the meal as a salad and tested its palatability on four people. One “wouldn’t mind eating this all week as an astronaut” while the others were less effusive in their praise, though still reportedly took second helpings.
In the future, the team plan to run the model again to find the most suitable combination of ingredients for a female astronaut, and also to expand the variety of crops in their database.
Their study was published in ACS Food Science & Technology.
In October, researchers presented a light, cellulose-based substrate that could function as a supportive base for one day growing edible plants on the Moon.
