What you're asking about is basically https://en.wikipedia.org/wiki/Kessler_syndrome https://en.wikipedia.org/wiki/Kessler_syndrome In general the question of

What you're asking about is basically https://en.wikipedia.org/wiki/Kessler_syndrome https://en.wikipedia.org/wiki/Kessler_syndrome In general the question of collision risk and debris is something evaluated for every launch/constellation. Starlink, for example, mostly avoids it being an issue by flying so low that debris quickly falls to earth and burns up in the atmosphere (they also design their satellites to fully burn up in the atmosphere). On the flip sides Starlink is planning on an order of magnitude more satellites than this. Even the worst case though doesn't really impact humans ability to fly to the moon/mars. You can make low earth orbit relatively unusable because there is a high collision risk if you hang out there for a year, but you should basically always be able to fly through low earth orbit to a higher orbit with negligible collision risk.