To be honest, I was actually distracted by the the swearing because it really was unnecessary writing. Like there are places where as an editor I would have told him to cut it too. --E.g., when he finds out what re-runs his crew member has and immediately follows the sentence with some cursing. It just would have been better with a lot of other literary devices.
Although some books will lose something if you subtract the harsher language, this is not one of them.
It's not necessary in any real sense, but a foul-mouthed astronaut who doesn't swear isn't a foul-mouthed astronaut. It's a trait that works well with the character's irreverent attitude.
I don't remember the language from when I read the book, so it must not have bothered me. I think given the situation the main character was put into, cursing makes a lot of sense. He's basically talking to himself day after day and clues the reader into his cowboy (in addition to science geek) like attitude. It also served as a bit of comedic relief for the character and reader.
Something was off about the swearing for me as well. Kept distracting me while reading the book. I’m perfectly OK with Bruce Willis foul mouthing his bloody way through a skyscraper. But for me this astronaut’s fucks are unimaginative, emotionally dull and repeating ad nauseam. I am reminded of Tourette syndrome.
Although some books will lose something if you subtract the harsher language, this is not one of them.