It really depends on how much junk actually is there and in what orbits; especially at 500 km up, space is big. The surface area of the earth is 510.100.000 squ

It really depends on how much junk actually is there and in what orbits; especially at 500 km up, space is big. The surface area of the earth is 510.100.000 square kilometers, at 500 kilometers the 'surface area' is a multiple of that (I can't math), surely there's enough gaps or lower-density areas at that height even if there was a catastrophic Kessler Syndrome event.