On board the International Space Station (ISS), it will not always be easy for Thomas Pesquet to eat in zero gravity. Certain foods can contaminate the ambient air or soil the equipment.

Credits Raphael Haumont

What do we eat in space?

Usually in space, astronauts eat freeze-dried dishes. Lyophilization is a principle of dehydration of a product by cold.
It was also developed by and for NASA. The product is frozen, placed under a high vacuum, so that the water, in the state of ice, immediately becomes vapor, without going through the liquid state, it is sublimation. The water therefore leaves the product and is captured by a refrigerant. In the end, this gives a dry product.

The main interest of freeze-drying is to keep the flavors, the colors, the vitamins. The texture is crispy or powdered. People often have the misconception of low-end dehydrated soups or dishes, but “real” freeze-drying can be very interesting.

Appetizing freeze-drying

The idea of ​​Thierry Marx and Raphaël Haumont was to create a different type of food for Thomas Pesquet.

They made “comfort food”, that is to say, “real dishes” in canned food, to be reheated. These are occasional meals that astronauts have with each other (birthday, weekend meal, etc.).

It is a “pleasure food”, which recalls childhood, its country, to exchange with the other astronauts on its culinary heritage, the culture of the country etc … The kitchen is an undeniable social bond, classified in the intangible world heritage of the ‘Unesco.

Dishes signed Thierry Marx for Thomas Pesquet

Starter dish dessert :

• Pressed potato, Roscoff onion and truffle.

Credits Mathilde de l’Ecotais

• Bazas beef, 7h cooking, porcini mushroom sauce.

Credits Mathilde de l’Ecotais

• Amandine with caramelized pears.

Credits Mathilde de l’Ecotais

Take up cooking and science challenges

The specifications were very complex. This is what motivated Thierry Marx and Raphaël Haumont. It’s a very exciting exchange between cooking, science, and also technique as they worked with maker Hennaff. Canning and canning are fundamental and they have the veterinary certificate validated by the European Space Agency.
The biggest challenge is zero health risk. The products are therefore canned.
Nicolas Appert perfected in 1795 a technique for preserving. The preparation is sealed in a box and heated to 110-120 ° C to kill germs, it is sterilization. To avoid health risks in the space station, the products are even “over-canned”. It’s at least 140 ° C for 1 hour and this had to be taken into account in the very design of the recipes.

Getty credits

• For the pressed potato or the almond cake, they took advantage of this technique to cook at the same time as they pasteurized.

If they had made a cake and ironed it again at 140 ° C, they would have had an overcooked cake, and too caramelized. They therefore cooked it during the sanitary process.

• For the beef, it is less serious because it was already cooking for 7 hours. Another hour at 140 ° C even gave it an even smoother texture, the collagen dissolved, and the sauce naturally thickened.

Thick sauces, modified textures

When you open a can, the sauce should not run all over the place, so the sauces should be thickened. Thierry Marx and Raphaël Haumont worked only on pectins, and on the collagen of meat, natural things, to thicken. No gums, starch or additives.

There is another challenge which is zero crumbs. The cake should not crumble, otherwise the crumbs remain in microgravity and they become air pollutants in the cockpit. It may seem like a detail but it is not easy to ensure the “cohesion” of a preparation. In the ISS (International Space Station), salt or pepper must be liquid. Obviously, there is no pepper mill, so they had to make a concentrated pepper extract.

Foods prohibited or difficult to use

They managed to make a wine sauce… without wine, for the zero alcohol side. At the laboratory in Orsay, they separated the pure alcohol from a wine, to obtain only the flavors and tannins. They took measurements to make sure there was no alcohol at all.

Thomas Pesquet loves mushrooms but they are real sources of microorganisms. It was therefore necessary first to make canned mushrooms, and then sterilize them with the rest of the dish because of the ban on the use of fresh mushrooms.

The nutritional profile is very strict

Concerning carbohydrates, lipids, proteins, fibers, they are very closely watched. Sodium intake, and therefore salt, is also highly regarded. There must also be little sugar, like the typical four-quarter recipe, to which Thierry Marx also added this challenge by removing the sugar. They worked on fruit pectins.

Everything must be rethought because feeding astronauts is a bit like feeding high level athletes. The weights are also imposed by the containers. Everything must fit, with the right weight, calories and taste.

The tastes must be strengthened, there is no aroma in the preparations. They concentrated the flavors by cold (cryo-concentration). A technique made in Orsay makes it possible to reduce a sauce, without heating, while keeping the flavors.

The more bland dishes in weightlessness?

The dishes seem more bland when tasted, and the aromatic profile changes. In weightlessness, the molecules do not move by convection. Concretely, if you open a box, the molecules do not go up in your nose. Astronauts are a little ageusia and anosmia, as if they were eating with a partially blocked nose. They have less flavor, so you have to concentrate them as much as possible.

As the environment is a bit noisy and the light is artificial, the feeling in the mouth is not the same, it is a bit like in an airplane.
Tomato juice is one of the most popular drinks on airplanes. In devices where you are at almost 80dB, you are more sensitive to salty and umami flavors (tomato, cheese, seaweed, etc.). You will turn, unconsciously to tomato juice, it is the same for the astronauts, their aromatic profile and their taste change.

Feedback on research

Beyond the culinary experience, Thomas Pesquet will teach many things. In this station, the astronauts are already confined, in overcrowding, they must take into account the waste, the on-board mass, and must be concerned to better manage their water resources.

It is exactly the same challenges for the earth. At the CFIC (French Center for Culinary Innovation), these issues have been integrated into the research. Work is being done on water recycling (freeze-drying, etc.), on the concept of waste and co-products, eat less eat better, and also on packaging. New packaging made from algae could be tested in microgravity. They are fully biodegradable, it is a trail for new containers.