Almost every astronaut leaving Earth does so through Russian territory in Kazakhstan. There, they board a Russian Soyuz spacecraft and travel to the International Space Station, which is largely built with Russian modules and operations. All of this would be impossible to do without the ability to speak, write, and read in Russian. Therefore, no matter where they are from, Astronauts must learn Russian as part of their training. The need for astronauts to learn Russian became mandated in 1998, after the ISS was first launched.