Research at the Institute of Life Technologies
Astronauts’ main sources of carbohydrates and protein are potatoes, wheat and soya. These staples are difficult to digest in their raw state, so it is essential to prepare them prior to consumption. For the second phase of the MELiSSA project, the ESA entrusted a consortium comprising the Institut Paul Lambin, the Institute of Life Technologies in Sion (Switzerland) and the companies GEM and SHERPA (France), together with RUAG (Switzerland), with the mission of taking a comprehensive approach to transforming these basic foodstuffs, bearing the challenging conditions in space in mind8.
While the nutritional aspect is dealt with by the Institut Paul Lambin, Laurence Nicolay is in charge of the area of the project related to the preparation and sensory characterisation of food. While at work in her pilot laboratory among a sieving machine, a hydraulic press and a universal cooking vessel, she explained that “First of all, it is about creating the widest possible variety. For example, potatoes can be steamed, boiled (with or without their skin), mashed, made into pancakes or flakes and so on.” The first challenge is to imagine all the different forms a foodstuff can take. Only a handful of plants in the Martian garden must feed the crew for several months, without meals becoming too monotonous.
Soft wheat will be transformed into unleavened bread, without the use of yeast. Laurence Nicolay explained “We must avoid introducing microorganisms to Mars, because they could prove difficult to control.”9Astronauts will use durum wheat to make pasta and bulgur, and soya to prepare pasta, milk, tofu and okara, a by-product from making soya milk, and rarely consumed in Western countries10. Laurence Nicolay underlined that “We must strive to make maximum use of all parts of the crops and create the least possible waste.”
Laurence Nicolay and her team work in the Institute laboratories, studying the whole preparation process from raw material to finished product. To analyse the preparation of unleavened bread, for example, the starting point is the grains of soft wheat, which pass through different stages: milling and sieving in a pilot mill to obtain flour, adding water and mixing in an electric kneading machine, rolling the dough out manually and cutting it, and then baking it in an oven. All the stages are meticulously documented to identify not only the amount of wheat required, but also the amount of water and electricity, and preparation time. They also record the volume and weight of the equipment used.
Each food preparation process undergoes a weight appraisal: How much weight has been retained? How much has been lost? Foodstuffs are precious in the MELiSSA ecosystem, so the aim is to obtain maximum yield. In addition, everything will function as a closed circuit. Thus, questions that might seem innocuous on Earth, take on an entirely different dimension when transposed to the Red Planet. As Laurence Nicolay asked “Should we peel the potatoes or not? If we peel them, what do we do with the peelings? Can they also be used as food?”
Another key aspect is the amount of nutrients in food both before and after preparation. Laurence Nicolay pointed out that “We must know the amount of macro and micronutrients.” Such data is essential, as it enables the preparation of meals that suit the specific needs of astronauts. Their calorie requirement can vary greatly, especially when it comes to spacewalks11. On space missions, energy intake is often inadequate: “Studies have shown that astronauts may be undernourished, because the food is repetitive and they lose the will to eat,” Laurence Nicolay continued.12 "For short voyages, the body’s natural reserves ensure this deficit is not overly damaging. However, for long-term journeys, such as those proposed to Mars, such a shortage could undermine the success of the mission and even the survival of the astronauts."
Hence the need to assign as much importance to the nutritional aspect as to the sensory impact: “Our goal is for astronauts to remain both physically and mentally fit. They must be able to vary and enjoy their meals so as not to become depressed or lose weight. They shouldn’t gain weight either, as they still have to fit into their spacesuits!” added Laurence Nicolay in jest.
Countering the loss of appetite proves to be vital. Despite its duration, a manned mission to Mars is more than likely to see the best-fed astronauts. Until now, astronauts took pre-packaged meals on their missions and had to put up with them. According to Laurence Nicolay, “Sure, they could choose what they wanted to eat but, sometimes, once on the mission, they lost interest in the meals they had opted for while on Earth.” The unique aspect of the MELiSSA project is that it will enable astronauts to produce and prepare their food themselves, while on the mission. This means meals can be personalised, which is quite a bonus when it comes to their acceptability.
