[jandrese]

It would take an unbelievably catastrophic Kessler syndrome to make it too dangerous to boost through LEO. It's not a game of Asteroids, we're talking about collisions on a yearly or possibly monthly timeframe. Bad enough to ruin LEO for satellites, but not so bad that it blocks you from space entirely.

[TeMPOraL]

I still think a believably catastrophic Kessler syndrome would be risky enough that NASA and others would refrain from sending manned missions through LEO at low inclinations.

It's not a game of Asteroids, but it's also not as thin as the asteroid belt.