This is the 260th most frequent Russian word.
российский
"Российский" means "Russian" (related to Russia as a state or federation).
Here, 'российский' describes the nationality or affiliation with Russia of the astronaut.
Российский космонавт успешно провел эксперимент на орбите.
The Russian astronaut successfully conducted an experiment in orbit.
In this case, 'российский' pertains to the geographical or cultural origin of the art.
Выставка российского искусства проходит в местной галерее.
An exhibition of Russian art is taking place at the local gallery.
Here, 'российский' refers to the country of production or association of the movie.