Where’s the Oxygen?

On Earth, our environment is made up of the perfect mixture of elements to sustain life. Oxygen is one of the most important of those elements. When you take in a breath, what happens? You can feel air going into your body through your nose or mouth. You can’t see it, but it’s there in the air. We breathe because our bodies need oxygen in the air. Oxygen is like food for our blood. We need it to survive.

In space, there is no oxygen. Because of this, astronauts do not breathe the same as they do on Earth. They have to breathe with the help of a protective spacesuit that supplies them with oxygen. A human being would not survive on a spacewalk for more than a minute or two without a spacesuit.

Compared to getting dressed on Earth, which takes just a few minutes, putting on a spacesuit takes 45 minutes. The astronauts must then spend lots of time breathing only pure oxygen before going outside the space station. This process is called prebreathing.

Without a protective space suit, astronauts would not be able to survive on space stations.