> upper stages designed to explode into a thousand pieces at the target altitude
By this do you mean at the 800km altitude?
By this do you mean at the 800km altitude?
Suffice it to say this is not sustainable for megaconstellations in thousand years orbits. The responsible thing to do with that kind of scale involves reliable, redundant, prompt de-orbit of upper stages, and ideally for high-thrust, high-mass, high-engineering-margin-of-error atmospheric upper stages never to make it that far into the mission.