I've already tried altering graphics settings. It was one of the first things I fiddled with. I suspect the cause was a mod update, and there's a conflict somewhere. I think one of the recent mod updates was aviation lights, so I'm going to try uninstalling that and see if it fixes things, and I'll get back to you.
EDIT 1: I will take another look at my graphics settings, too, because there's one thing I didn't think of. I can't remember what the particular setting is called but I'll know it when I see it. I turned it down the other day to see if it would help my frame rates around a big station I'm building. Turns out, it didn't, so it's pointless turning it down anyway.
EDIT 2: The setting is called 'Render Quality' and, it turns out, having it set to 'fastest' is causing the problem. I turned it up to 'fantastic' and no issue, but I haven't tested anything in between, so I'm not sure what the cutoff is. For now, it's working as intended, and I'm happy. I'm especially happy that it wasn't a mod conflict, because I do liek me dem aviation lights.