Hello; There is a lot. So much so that at some point in the future we may be essentially trapped on earth. As the many thousands of space junk in stable orbits collide with each other they make more space junk. For decades we have been launching lots of stuff with no future thought of the consequences. If I recall correctly to reach earth orbit things need to be boosted to 17,000 MPH or so. So even small stuff going that fast can take out satellites and space stations.there is quite a bit of junk floating around up there.
the brains out there would be able to nail the time better.
Hello; I think the problem may be that the orbit is decaying as it encounters drag from the thin upper atmosphere. That upper atmosphere is in flux and it is hard to predict just when the atmospheric drag will be more or less intense.