There won’t be life on Mars if we can’t feed the astronauts
Could you live on dehydrated TV dinners for five years?
Food technology scientist Grace Douglas is working at Nasa’s Johnson Space Centre to improve preservation methods in anticipation of a 2030 mission to Mars.Previous space missions have stretched the lifespan of food for up to 12 months, but to get a crew to Mars Douglas’s team will have to push the limits of technology and create meals that are compact, nutritionally balanced and somewhat tasty. Oh, and they have to last for five years.
In the past food for space missions was freeze-dried to prevent spoilage and food poisoning. Food that could not be freeze-dried was thermostabilised, a process of vacuum-sealing and heat-treating food to remove bacteria. This technique is not viable for the Mars mission, however, because blasting food with heat, years before it is eaten, causes degeneration of both the taste and nutritional value. Douglas is working on refining moisture- and oxygen-resistant packaging, as well as the thermostabilisation technique. Of her project she says: “In general nothing has a five-year shelf life, and for a mission for Mars we need a five-year shelf life.”Keeping the vitamin levels in food high is another big concern. Even in frozen food vitamins slowly degrade as they react with oxygen, and in the depths of space it would be easy for astronauts to miss out key vitamins. For Douglas, this means designing a menu that contains tasty and familiar foods that astronauts aren’t going to get bored of eating. A diet of Soylent-style shakes might fulfil their calorie and vitamin requirements on paper but there’s no guarantee that astronauts would actually eat it.When the astronauts are tens of millions of kilometres away from Earth, a familiar menu would provide a much-needed link back to home. “Any time a person’s normal sources of gratification are denied, food takes on additional importance,” says Jack Suster, a researcher who advises Nasa on the wellbeing of space crews.It is likely the crew will eat a combination of freeze-dried meals, to which hot water is added to make a complete meal, and thermostabilised meals, which once heated are ready to eat. On the menu is macaroni and cheese, spaghetti and meatballs, pizza, tacos and a variety of meat and vegetable stews. According to Nasa the most popular food item is the flour tortilla, which provides a handy edible wrapper to any meal and is the number one requested item by astronauts on the International Space Station.Along with improving preservation methods, the team is also experimenting with regenerative food systems that may let astronauts grow certain items within the spacecraft and later on Mars, although Douglas says there is no chance that they will rely predominantly on growing crops on Mars. On the menu are unconventional agricultural crops like crickets, algae and fungus – plants that grow like weeds and require little water.