Maybe I am misremembering but there was a story with two threads alternating each chapter.
One thread was inside a spaceship with detailed descriptions of surroundings and daily life. I remember reading until there is some kind of battle he gets on a smaller ship with a crew but i don't remember their goal.
The other was about a boy that crossed a river and gets stranded away from his tribe. Then, he travels the land with centaurs. Also, very detailed descriptions of the environment and his survival.
I would like to know if someone remembers the name of the story or if they are two stories I may have read at the same time.