So, to become an astronaut you currently need to know Russian? What other languages do you think they will add in the next 15 years? I was thinking chinese, but I was wondering other people's thoughts?
Well it seems the reason Russian is required is that there is a mission control center located in Russia. So in case an emergency occurs aboard the ISS while it is over Russian mission control, astronauts need to be fluent so they can understand the instructions they receive. Here's the article I read if anyone's interested.
As for which language is likely to be added in the next 15 years, it may very well be Chinese. China is scheduled to have its own space station completed in 2020 and the ISS is supposed to retire in 2024 so perhaps the Chinese space station will be the next site of international cooperation in space exploration.