Not to be alarmist, but suppose a galactic federation judges that
humans in their current state of development will pose a danger to
other civilizations when they imminently attain warp capability, so as
a safety precaution they need to be confined to their planet for at
least a millennium. An agent of the federation posing as human
manipulates the population into allowing 100,000 satellites to be
deployed. With that done, federation scientists solve the many-body
problem for the exact necessary speed and trajectory of a small meteor
to shatter one of the satellites such that some of its fragments
precisely target its neighboring satellites, and so on, while the rest
get kicked up into higher orbits. Life goes on but any enterprise that
depends on penetrating the debris field becomes infeasible.
replyWhy is that?
replyDepends on how you define LEO. I think the commenter was probably thinking of Very Low Earth Orbit, VLEO.
replyFirst graph is a list of deorbit times: https://www.nasa.gov/smallsat-institute/sst-soa/deorbit-syst...
As expected, higher altitudes, higher mass, and lower surface areas correlate to longer deorbit times. It looks like altitude has an extreme effect on deorbit times, as you can see the 100 KG satellite (solar min) deorbits in a little under 2 years at 400 KM, but over 15 years at 500 KM. So 1.25x the altitude results in 7.5x the deorbit time.
Stuff at 800-1000 KM can take centuries to deorbit, and that's within both NASA's (under 2000 KM) and the ESA's (under 1000 KM) definitions of LEO. There is a definition for VLEO of under 450 KM, which would have fairly short deorbit times, and therefore a relatively mild Kessler Syndrome.
Indeed. It's something investors should worry about for the data centres and if SpaceX will bankrupt itself instead of giving them a return on their investments, but it's not something where general space enthusiasts should worry about Starlink: the timescale for orbital decay is long enough to kill a company, but short compared to a lifetime.
replyBecause LEO is a degrading orbits, meaning that the satelites fall out of orbit after a few years on their own.
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