> You have to go through the lower orbits to get there
Math doesn't math.
The closest solution I've seen is putting 10^6 to 10^9 kg fragmented debris in the 700 to 1,000 km band to create a 5% failure rate at fastest transit, which is economically devastating. But that assumes away grain-grain collisions.
I think when I last ran the math, you'd need to sustain 5 to 10 Starship loads of fragmented debris to that orbit a week to create a proper barrier–near 100% hazard. At which point the solution becomes shooting down those launch vehicles. In a couple years (3 to 10, depending on the solar cycle), the skies would clear to about 1% hazard. That hazard, however, would persist for some time–how long is anybody's guess.
Math doesn't math.
The closest solution I've seen is putting 10^6 to 10^9 kg fragmented debris in the 700 to 1,000 km band to create a 5% failure rate at fastest transit, which is economically devastating. But that assumes away grain-grain collisions.
I think when I last ran the math, you'd need to sustain 5 to 10 Starship loads of fragmented debris to that orbit a week to create a proper barrier–near 100% hazard. At which point the solution becomes shooting down those launch vehicles. In a couple years (3 to 10, depending on the solar cycle), the skies would clear to about 1% hazard. That hazard, however, would persist for some time–how long is anybody's guess.