Maya, this looks like it was written by a Russian and not a native English speaker. I apologize if you wrote it - maybe I can help you make it more natural.

Actually, its not me who wrote this)). However, it's no doubt I have a lot to improve in my English. It is from a special English language textbook for post-graduate students. The book was prepared by a team of authors who are philologists themselves. They are Russian native speakers, you are right)). I sometimes feel that there are a lot of incorrections in this book.
But, I have to help my student with the tasks in the book. S\he is taking a post-graduate course there to become a PhD.

I just found the entire paragraph online. This makes me so sad.

To start with, there’s no such thing as a foreign cosmonaut – cosmonauts are only Russian :(

And, I would be happy to know how this utterance would sound more natural.