So, I read recently that it’s very very unlikely anything will hit and damage Voyager 1 whilst it’s on its mission, but I also read about astronauts having to fix parts on ISS because small pieces of space debris that travel at really fast speeds and cause damage. This seems contradictory to me, how could we be so positive nothing would‘ve/will cause Voyager damage, but there’s things in space causing the ISS damage?

I know it’s been travelling for like 40 years, and not been damaged, but I just need to know how it hasn’t been hit by anything and how scientists were so sure it wouldn’t get hit? Sorry if this is a silly question