That's the claim made, yes. Now, how many other satellites are likely to get hit in "5-10 years" of flak flying around at orbital velocities? It's nice if you

That's the claim made, yes. Now, how many other satellites are likely to get hit in "5-10 years" of flak flying around at orbital velocities? It's nice if your goal is to say "Well, it probably won't render space useless forever..." - but that assumes one collision, and no ongoing collisions. If it's "5-10 years per collision," and each new one resets the 5-10 years timeframe, well, there's a lot of stuff up there that can make a mess. Unfortunately, the low orbital shells are also "everywhere." It's not like geosync orbits where if you Kessler them, well... not going to have geosync stuff anymore, but you can still use other orbits. If you Kessler LEO shells, you pretty much have a high risk of anything you try to send to space getting blasted on the way up. It doesn't take much of a bit of debris, at orbital speeds, to trash your booster and make you have a bad day. I guarantee a bolt at 17,000 mph will do some damage (typical LEO velocities) - that's about ~22x the speed of sound in the atmosphere, depending on altitude. If there are tens of thousands of things up there and you start things colliding and blowing up, you've basically put a defensive shell around the earth for a century, if not longer, by the time all the satellites get fragged and the debris eventually comes down.