A collision event is considered any event where a satellite passes within a ridiculously large distance of another satellite. It doesn’t mean they’re necessarily going to collide.
In the incredibly unlikely event that all of the things that you have stated happen everything would clear out within 12 to 18 months which given the fact you’ve just decimated 21st century civilisation is probably the least of everyone’s concerns anyway.
A solar flare is just one example of many possible causes. There are plenty of other ones. You didn’t touch on any of the others so let me explain - NASA reports on small satellite missions show that about 40% of satellites experience at least partial mission failure within their lifetime. Studies have shown the leading cause of satellite failure is propulsion systems, responsible for about half of all failures. This is not uncommon at all.
Most altitude ranges in LEO still have debris from decades ago, the exception being below 300km, which is basically still in the atmosphere. Unfortunately, debris strikes have regularly produced debris that are flung into higher orbits, so even collisions between satellites in this range are dangerous.
Edit: I also forgot to mention, the five day estimate (now three days actually) wasn’t for a close-call, it was for a debris-generating event.
A collision event is considered any event where a satellite passes within a ridiculously large distance of another satellite. It doesn’t mean they’re necessarily going to collide.
In the incredibly unlikely event that all of the things that you have stated happen everything would clear out within 12 to 18 months which given the fact you’ve just decimated 21st century civilisation is probably the least of everyone’s concerns anyway.
A solar flare is just one example of many possible causes. There are plenty of other ones. You didn’t touch on any of the others so let me explain - NASA reports on small satellite missions show that about 40% of satellites experience at least partial mission failure within their lifetime. Studies have shown the leading cause of satellite failure is propulsion systems, responsible for about half of all failures. This is not uncommon at all.
Most altitude ranges in LEO still have debris from decades ago, the exception being below 300km, which is basically still in the atmosphere. Unfortunately, debris strikes have regularly produced debris that are flung into higher orbits, so even collisions between satellites in this range are dangerous.
Edit: I also forgot to mention, the five day estimate (now three days actually) wasn’t for a close-call, it was for a debris-generating event.