To elaborate, even a minor conflict in orbit runs a high risk of causing a chain reaction which turns most satellites into a cloud of orbital velocity debris. This cloud will make it impossible for any spacecraft to operate beyond that altitude for hundreds of years. We will have confined ourselves to this planet.

Even with the current situation which is infinitely better than what post-conflict would look like, avoidance of debris is a major concern when planning space missions.

https://en.wikipedia.org/wiki/Kessler_syndrome