Breathe in flight the astronauts?

When creating space ships had, of course, to provide normal conditions for the messengers of the Earth, leaving the planet. The first and most important task was to give the astronauts gas environment required for a full breath. Soviet and American designers went to this issue in different ways. On our ships provided with the same environment, that of the earth. Astronauts breathe atmospheric air. To solve such a task was not easy, but it was solved. American astronauts breathe pure oxygen under reduced pressure. It's easier, but more dangerous. One day when preparing the spacecraft for launch on Board there was a fire that destroyed the crew.
docking of the Soyuz-ApolloThus, the Soviet and American astronauts in literally breathe a different air. During the docking of the Soviet and American ships had specially to provide airlock. To enter an American ship Soviet cosmonauts came into this camera, it was pumped the air of our ship and fueled oxygen American. Only then opened the entrance to the ship Americans.