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.

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.

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

In the kitchen with Chris Hadfield!

Follow Chris in the kitchen as he prepares a treat in microgravity on board the ISS!

Meal preparation in five steps

The standard procedure for preparing meals on the ISS is as follows:

1. Reheat the meal in the conduction oven or rehydrate it according to the instructions.
2. Prepare the beverage by rehydrating it with hot or cold water.
3. Cut the meal packaging with scissors.
4. Eat the meal from the package and drink using a specially adapted straw.
5. 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 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?

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

Explore further

• Living in space
• International Space Station
• About the job