Even now satellites will come crashing back to Earth. However, once they’re reached the weightlessness of space why do they come crashing back down?
One reason is if the satellite is no longer of use, usually due to an unrepairable problem. And if they leave it there is could disintegrate and cause problems for other satellites.
Sometimes they’ll choose to move the satellite into a slightly higher orbital band, known as the “graveyard orbit”. But other times, if they can, they’ll control it’s fall down back to Earth. When this happens the plan is usually for most of the satellite to disintegrate on re-entry and then for the remaining pieces to fall harmlessly into the sea.
Other times satellites will fall down themselves after moving too low in the orbit and being pulled back into Earth’s atmosphere. On the rare occasion this happens though most of it disintegrates on re-entry and even then the chance of your being hit by any of the debris is 1 in 22,400,000,000,000 – that’s good to hear!