Eating in space
On Earth, people like to get together to share a good meal. The same is true on board the International Space Station (ISS)! For astronauts, this is an opportunity not only to refuel, but also to relax, spend some quality time with colleagues and discuss their culture.
Canadian astronaut Robert Thirsk and the crew of Expedition 20/21 share a meal during their six-month mission on board the ISS. (Credit: NASA)
On the menu in orbit
Eating in microgravity is not always a piece of cake! Some foods can contaminate the ambient air or foul the equipment. Astronauts must take care at meal time.
Just like physical activity, a healthy diet helps reduce the negative effects of microgravity on the human body.
Food must meet certain criteria to be allowed in orbit:
- Compact: Space is very limited on board the ISS.
- Lightweight: Sending goods into orbit is extremely expensive.
- Nutritious: The food must contribute to the healthy diet of the crew.
- Tasty: Astronauts' sense of taste is reduced in microgravity.
- Sticky or wet: In the absence of gravity, crumbs and particles float freely.
- Processed or pasteurized: The food must keep for at least the entire duration of a mission.
Text version - Astronaut Food – What do space explorers eat? - Infographic
This illustration gives an overview of what food they eat in space and how they prepare it. (Credit: Canadian Space Agency [CSA])
To facilitate matters, there is a permanent ISS menu. This eight-day menu consists of three meals and one snack a day. It was designed to ensure that astronauts have a balanced diet during their stay in space.
In addition, dieticians ensure that all the menus contain between 1900 and 3200 calories per day, depending on the astronaut's:
- weight
- gender
- specific needs
Crew members of Mission STS-127, including Julie Payette, participate in a taste test at NASA's Johnson Space Center. Dieticians (bottom right) are also on site. (Credit: NASA)
Here is a glimpse of what was on the menu for CSA astronaut David Saint-Jacques. (Credits: CSA, NASA)
In the kitchen with Chris Hadfield!
Follow Chris in the kitchen as he prepares a treat in microgravity on board the ISS!
See how to prepare a sandwich in microgravity with three ingredients: tortilla, peanut butter and honey. (Credits : CSA, NASA)
Chris makes like Popeye and transforms dried space greens into a delicious source of nutrients and iron! (Credits : CSA, NASA)
Transcript of the video Chris' kitchen part deux: space spinach strikes back
Chris prepares a chocolate cake and a coffee for dessert. Be careful: it's hot! (Credits : CSA, NASA)
Meal preparation in five steps
The standard procedure for preparing meals on the ISS is as follows:
- Reheat the meal in the conduction oven or rehydrate it according to the instructions.
- Prepare the beverage by rehydrating it with hot or cold water.
- Cut the meal packaging with scissors.
- Eat the meal from the package and drink using a specially adapted straw.
- Catch any stray food with a utensil... or your mouth!
Food conservation
Most meals in the ISS have been selected and packaged so as to ensure that they will last for the entire duration of a mission. A small sticker indicating the expiry date is also affixed to each food item.
Food consumed in space falls into six categories:
-
Fresh- Fruits
- Vegetables
-
Natural form- Nuts
- Tortillas
-
Dried- Dried fruit
- Dried beef
-
Irradiated- Chicken breast
- Smoked turkey
-
Rehydratable- Spinach
- Juices and beverages
-
Thermostabilized- Tuna salads
- Vanilla flan
Fresh foods can be delivered periodically to the Station by cargo vessel. Ground crews sometimes include a few fresh fruits and vegetables—a real luxury!
Thermostabilized foods have been heat-treated, while irradiated foods have been subjected to ionizing radiation to destroy certain microorganisms. The goal in every case is to preserve the foods.
Taste in microgravity
Does food taste the same in orbit as on Earth? Yes and no!
When they first arrive on board the ISS, most astronauts experience the sensation that their head and sinuses are congested: the effect is similar to having a cold.
On Earth, the heart must work harder to pump blood to the head, against gravity. However, in orbit, in the absence of the downward pull of gravity, bodily fluids tend to rise to fill the head and sinuses.
However, after a few days, the situation improves. Still, flavourful foods are particularly appreciated!
How do astronauts season their meals in space?
CSA astronaut David Saint-Jacques shows us how astronauts season their meals aboard the International Space Station. (Credits: CSA, NASA)
Transcript of the video How do astronauts season their meals in space?
Following resupply of the ISS by a Soyuz capsule, Canadian astronaut Chris Hadfield enjoys a blood orange, a rare snack in orbit! (Credits: NASA, CSA)
Astronauts' special requests
Astronauts test certain foods several months prior to the launch of a space mission.
To add variety to the standard ISS menu, crew members can also request some of their favourite foods or foods typical of their culture, as long as they are suitable for the Station's environment.
For example, during Chris Hadfield's stay on board the ISS, the other crew members had the opportunity to taste some Canadian foods such as:
- maple syrup cookies
- duck rillettes
- candied wild smoked salmon
Finally, the astronauts' families sometimes send them special foods... more as a little taste of home than strictly for their nutritional value!
Chili for space
David Saint-Jacques enjoys a special chili, inspired by his wife's recipe. (Credit: CSA)