Profanity in a science fiction story?

It's fine. Science fiction is my favorite genre and almost every book had profanity in it. As long as it's not constantly in use, it should be fine.

Well today's swearing has it's place, although you may give some readers pause if you use swear words depending on how you use them. I would say the least objectionable way to use swearing would be for characterization. If you only have one character in the book who swears, their vulgarity says a lot about them as a person and may help imersion rather than breaking it, as it helps one understand the character. Also if you want to go this route, reactions from characters who don't swear to the more vulgar one's swearing can help characterize them, too. The character who has a "Well, I never!" reaction and the character who just rolls their eyes or completely ignores it are revealed to be very different simply by adding a sentence, or conversely, a lack of acknowledgement.

However, since you are writing a Sci-Fi novel, you have an option not open to most other genres that may serve as a happy medium: Have you ever considered inventing your own swear words? Language is constantly evolving and changing after all, and is varied country to country (For instance, swearing basically isn't a thing in Japan. There is no stigma associated with "Kuso" which is basically their catch-all swear which can be translated as Sh*t, F*ck, or D*mn.) So one could feasibly expect that swearing would sound different in another time, or on another planet. You don't even necessarily need to come up with new definitions, just swap a modern swear word with some other invented word, and allow context and character reactions to make the words 'swear' status clear to readers. This method allows you to have even the most vulgar of character while not breaking, and if done well, even increasing, immersion.

As long as it's not children's or middle grade, of course. People swear, it's a fact of life, so why shouldn't characters in a book do the same? Make sure you're not just throwing it in there just because you can though. Not everyone uses profanity, so neither should all your characters.

I personally like a bit of cursing in a book. Makes it feel more realistic, considering we live in a world where the majority use swears everyday.

But hey man, you pretty much answered your own question, you know.

Foul language can really make the reader stumble and pause and I doubt that is what you want.

This is a fairly modern era, so weave some in if it is character specific -- but, in general, it can make the reading experience stilted.

How much swearing was in the last 20 recently-published science fiction novels that you read? That, on average, is how much you should expect to get away with.