> Half of fragments are toward a lower orbit. The other half only boost apogee and either lower perigee or leave it unchanged. I think this is something that's

> Half of fragments are toward a lower orbit. The other half only boost apogee and either lower perigee or leave it unchanged. I think this is something that's not intuitive to othe average person. Basically: a collision can change an object that's in a circular orbit into an elliptical orbit with a higher apogee. But it can't circularize the new orbit higher without a 2nd "burn"[1]. Which means that if a satellite that would passively deorbit in a short amount of time is in a collision, it is necessarily true that all of the fragments will also deorbit in a small multiple of that time. > Basically, Kessler is not a concern at VLEO altitudes. Unfortunately most proposed Starlink competitors cannot afford to launch the thousands of satellites necessary for a viable VLEO constellation and instead are launching dozens or hundreds into LEO orbits which aren't self-clearing and do pose a Kessler concern. Thankfully, Kuiper will be just above Starlink. From what I understand, their passive deorbit times are ~10-20 years. The real problem is with OneWeb and the upcoming Telesat Lightspeed which are both at 1000km+. It sounds like OneWeb was planning on a greatly expanded next generation constellation, but they've since scaled their plans back and are incorporating bandwidth from geostationary satellites into their offerings. --- 1. https://en.wikipedia.org/wiki/Hohmann_transfer_orbit https://en.wikipedia.org/wiki/Hohmann_transfer_orbit