How many astronauts can the ISS hold?

Life in space

Science & Exploration

During their stay on board the International Space Station (ISS), the astronauts must live and work in an environment that is very different from the environment on earth. There, too, they have to wash themselves, go to the toilet, eat, drink and keep fit and healthy. All of these activities must be adapted to the weightless conditions that prevail on the ISS.

The ISS orbits the earth at an altitude of 400 km and everything has to be transported there. This means that the astronauts have to store resources such as water and food and produce as little waste as possible.

In this series of video clips recorded during the OasISS mission of ESA astronaut Frank De Winne, he and his crew colleagues explain how they live on board the ISS. The online lesson can be incorporated into curriculum classes on personal care, food and nutrition, and exercise and health.

The day begins: Personal hygiene on board the ISS:

Whether at home, at school or on vacation - personal hygiene must be taken care of every day. What does that mean? Well, wash yourself, brush your teeth, go to the bathroom, and put on reasonably fresh, clean clothes.

Even the astronauts on board the International Space Station have to take care of their bodies. In such a small space that you sometimes have to share with up to 13 people, it can be very uncomfortable when someone lets things slide!

Let's start with the basics:

teeth

Why do we have teeth and what is their function? How do we take care of our teeth? Why is dental care important? Write down all the reasons you think teeth are useful.

Take a mirror and take a good look at your teeth. How many different types of teeth can you see and feel? - The sharp teeth in the front of the mouth are called Incisors. The pointy teeth next to it are the canines and the thick teeth with the bumps are called anterior and posterior molars. As it grows, the milk teeth fall out and the 'second' teeth come out. We keep them all our life and that's why it's important to take good care of them!

Count once how many teeth you have. Draw your teeth as you see them in the mirror and try to label all parts (enamel, gums, jaws ...). Find out what the different parts do.

Experiment to try: the effect of cola on teeth

If you have a tooth that has fallen out, such as a baby tooth, put it in a glass with Coke or any other carbonated beverage that you enjoy drinking. Check back every day for a week. What happens to the tooth?

Photograph the tooth before and after it sits in the drink. Do you know why he's changing? Can you guess why it is important to reduce the amount of soda drinks we consume?

What's in the fizzy drink that damages the tooth?
Why do we use toothpaste?
How often do we need to brush our teeth with toothpaste?

Reply:
Most young children have 20 to 25 teeth in their mouths. Brushing your teeth is important to protect your teeth from decay and bad breath; when we stop brushing our teeth, we get bad breath, toothache and teeth get pitted.

Fizzy drinks contain acid (carbonic acid) and can damage tooth enamel. Brushing your teeth with a fluorine-containing toothpaste after a meal can help prevent tooth decay and strengthen your teeth. It also gives our mouth a fresh smell!

One of the first things we do after getting up in the morning is brushing our teeth. Why is it necessary?

When eating, a little bit of sugar from the food remains in the mouth. Bacteria feed on this sugar and form acid. This acid dissolves the tooth enamel and can cause holes (tooth decay). That hurts! (Toothache) To be certain that this will not happen, we have to go to the dentist's check-ups regularly. Everyone has to keep their teeth healthy and clean - even the astronauts in space! If you get a toothache, the dentist is very far away!

In space:

Astronauts brush their teeth as we normally do. There is only one difference! See how everything 'floats around'.

This is because there is no weight acting on the International Space Station (ISS) that pulls everything down like it does on Earth. The space station orbits the earth so fast (2800 kilometers per hour) at the correct speed and direction that it does not fall down on the earth, but keeps falling around the earth. As she falls, everything inside is weightless. So everything is floating around!

Even water and toothpaste. The toothpaste can be swallowed after brushing (edible toothpaste) and the mouth is then wiped with a wet cloth. The astronauts have to keep their mouths closed as much as possible when brushing their teeth so that the toothpaste doesn't float out!

Use of the toilet on the ISS

But if everything 'floats' in space - how do you go to the bathroom? There is a special toilet on the ISS (in the Russian module Zvezda). Now that the entire crew is on board, another is being installed in the US module.

The astronauts have to strap themselves in to avoid floating away. Instead of a flush toilet, we have a suction tube that pulls the waste into a hole with an air jet. The solid waste is compressed and stored for later disposal. The urine is collected and then sent for recycling. This is, without a doubt, a strange way of going to the bathroom!

Eating and drinking on the ISS

Just like exercise, diet also plays an important role in the health of astronauts.

Food is not just there to provide astronauts with enough calories to work. Rather, meals are important social events for people so far from their families and friends.

The dishes are specially prepared, because in weightlessness special factors have to be observed so that the food does not float off the plate. Also, there are certain foods that must be eaten to counteract the effects of adapting to the space environment.

Astronauts can choose their dishes, provided that the nutritional values ​​and calories are within acceptable limits: 2800 calories per day. The food trays are put together for each astronaut on Earth and transported to the ISS before their arrival. They are stored and labeled in one of the modules. Red food trays contain food from Russia and blue trays contain food from American / European countries.

The food must undergo a special treatment so that it has a long shelf life and low mass.

Space food

There are several types of foods that are eaten in space:

 

  • Rehydrable food:To make it easier to store the food, the water is removed from them. This is also called freeze drying. On board, these foods are given water again before consumption. These include beverages (tea, coffee, orange juice) and cereal flakes such as oatmeal.
  • Heat-treated foods: Heat treated food that can then be stored at room temperature. Most types of fruit and fish (tuna) come in cans with easy-to-peel lids. Desserts are packed in plastic bowls.
  • Irradiated foods: Most beef products are cooked, packed in flexible film bags and sterilized using ionizing radiation so that they can then be stored at room temperature.
  • Fresh food: such as apples and bananas - newly arriving crews often bring fresh produce with them.
  • Untreated foods: for example nuts and cookies.

The astronauts use the trays as plates and all food has to be squeezed out of either a tube or a bag. Can you imagine what would happen if the drinks and crumbs could float around freely? Look at all the electrical appliances ... right, it would be a disaster!

It is very costly to get all the food and water to the space station. Therefore everything has to be very light and be able to be stored as easily as possible.

Experiment: We compare how ripe fruit turns brown or spoils in the air with and without chemical treatment

Material:
Distilled water, apples, bananas, celery sticks and carrots, vitamin C tablets. Small plastic bowl, knife, spoon and paper plate.

Introduction:
What happens when we put foods like apples and bananas in the air? This brown color spoils the food. In space we need to save space and weight in the case of certain fresh foods and avoid waste such as shells and housings or cores. The food must also be packaged in the form of individual portions. For this purpose, fruits and vegetables can be cut into slices and protected against the influence of the air.

We will see how this is done with the help of a chemical inhibitor.

Execution:
1. Fill two small, deep bowls with water. Dissolve a vitamin C tablet in one bowl and leave the pure water in the other. Label the bowls accordingly.
2. Cut a fruit into six equal-sized slices. Put two pieces in each of the liquids. Make sure they are completely submerged and wait 10 minutes.
3. Place the remaining two pieces on a paper plate labeled 'untreated'.
4. Then take the individual pieces out with a spoon and place them on separate paper plates.
5. Repeat the process with different fruits and vegetables.
6. Let all three plates sit for an hour and see if the pieces turn brown.

Discussion:

  • Which fruits and which vegetables have not turned as brown as the others?
  • Can you think of another chemical inhibitor that can be used to preserve fruits and vegetables and is also edible?
  • See if the amount of vitamin C affects how quickly fruits and vegetables turn brown. How do you best go about this?

Reply:

  • The foods treated with vitamin C are the least spoiled. This is because vitamin C acts as an antioxidant and inhibits the effects of oxygen on food (the brown color).
  • Sugar, salt, acids (vinegar) ...
  • Suggestions: Cut the vitamin C tablets in halves and quarters and dissolve them in the same amount of water as the whole tablet before. See if the lower dose has any effect.

Sport and fitness

The human body evolved on earth, in a gravity field. Weightlessness makes even the smallest of tasks difficult. The astronauts have to anchor themselves firmly in order not to float away - even using the computer is difficult. Outboard missions can be very strenuous and place unusually high stress on your muscles.

This means that astronauts must take time to exercise to keep themselves fit and healthy so that they can do their jobs on the ISS and return to Earth in good shape. There is a treadmill and a bicycle ergometer on board (without bikes!). The astronauts have to train for at least two hours a day to stay in shape.

There are also pulleys and ropes, similar to those in a gym on earth, that they can use to do weight training. All of this helps keep your bones and muscles healthy, which is also important for returning to Earth's gravity field. This will keep your physical condition as good as possible.

Thank you for liking

You have already liked this page, you can only like it once!