I don't think we'll have a catastrophic cascade leading to Kessler syndrom even if these two satellites collide today, but few more such events might be enough.
EDIT:
Also, the collision will be off-center and, eyeballing the orbital diagrams, some 15 degrees shy of being head-on. That means you can expect most of the both satellites not being directly involved in the collision, but instead gaining spin and breaking apart under stress. Those surviving pieces will then keep most of their orbital velocity and heading, but scatter like buckshot, each piece on slightly different orbit, migrating further over time.
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[0] - https://www.spaceacademy.net.au/watch/debris/orblife.htm
[1] - Orbital decay due to atmospheric drag is a function of mass to area ratio. I'm not sure whether the debris from a hypervelocity collision tends to be more like irregular, high-drag shatter, or like low-drag spheres of superheated metal that cooled off radiatively.
How can we tell it will be off-centre if there's enough uncertainty in the orbital prediction that they are only "1% to 20%" to collide at all?
~ 150 km making single orbit becomes impossible.
~ 300 km orbital decay is ~km/month, so it already takes years to fall down to earth. ISS is at 400 km and decays 2 km/month. It has unfavourable mass to area ratio due to all those solar panels.
~ 500 km it takes few decades to fall down. (Hubble space telescope is here)
990 km is the altitude where these two satellites might collide. Debris can stay up thousands of years .
See the video by Kurzgesagt - “End of Space: Creating a Prison for Humanity.” [1]
> This might effectively lock use of Earth orbit away for centuries.
It would make exiting earth orbit and placing an object there significantly more complicated because you would need to take into account debris, probably detect them from the object and manoeuvre a lot more but it wouldn't entirely lock up use of Earth orbit. It would also be a solvable situation. Cleaning debris is doable.
Prompted by a comment from someone yesterday, I actually replayed the Snow Crash audiobook in the evening. Comparing SC and SE I notice that SC feels quite juvenile. I didnt notice that as much when I first read it in my 20s. But these days, it feels a bit too much over the top. Contrary to that, SE somehow feels too grown up.
Spoilers. Like, I mean, this isn't a plot summary, but this is in some sense what happens so look away now if you wish you didn't know:
The Primer has been calling her Princess Nell for a long time. Once you realise what's going on with the vast number of "specially adapted" Primers for the orphan girls, that Princess has got a ready made tribe with shared values in the form of the Mouse Army, waiting for her say so.
The whole book has been telling you that in this era what matters isn't control over a land mass, which is what the Fists are fighting for in the Leased Territories on behalf of Han, but a Tribe with shared values.
The Mouse Army shows up, rescues Nell and takes her to her mother. The Victorian Queen recognises Nell as the leader of a novel but important tribe.
The novel is flawed in many usual Stephenson ways (e.g. use of rape in place of actual character development) but I don't know what people expected from these endings, they seemed perfectly satisfactory to me on multiple re-readings.
i heartily recommend the whole series. i made a mistake in the post before - the post assumes 2.3% yoy.
This is in conflict with the Kurzgesagt video. I wonder what their source was for the Kessler effect preventing excursions into space altogether.
The risk will be much lower (you'll be spending very little time in the band filled with hypervelocity bullets), but it'll also be much more expensive. You'll need a much bigger rocket.
We don't worry about hitting an asteroid if going through the belt, because the density of objects is so low.
If you wanted to stay in the asteroid belt you would have many more opportunities for a collision, so avoiding asteroids becomes a lot more important.
What's the likelihood of any given collision like this initiating a space debris chain reaction? I'm guessing it's fairly low for any given collision, but quite high if we continue to allow collisions to happen. Would love to hear from someone who knows better than I do, though.