Ukrainian language for foreigners

Do you want to become an astronaut?
In fact — this is not a joke. All cosmonauts are now obliged to learn the Russian language, since the most important achievements in the field of space research, spacecraft and rocket construction belong to the Russian.
But if, as it were, descend from heaven to earth, and imagine a foreigner who came to study or work in a country with a Russian-speaking population, then the benefit of studying the Russian language is obvious.
What feelings does a person experience in an unfamiliar country, not knowing the language, culture and customs? — A feeling of complete isolation and misunderstanding among strangers.