Reacción a "Reactions to the fall of a large Chinese rocket fragment to Earth have closed part of the airspace"

Uncontrolled rocket bodies and satellites reenter every one or two days. What is special about this Chinese stage is its large mass, about 20 tons. It was the 4th of this type placed in orbit: The second reentered over the Indian Ocean, but the first and the third ones scattered debris on the ground as well, in Ivory Coast (2020) and in Borneo, at the end of July this year. Due to the fact that 88% of the world population is overflown by this stage trajectory and considering its large mass, the probability of someone in the world being hit by a falling debris, between 42° north and south, is about 1 in 500, i.e. more than the 1 in 10,000 threshold for which, at international level, a controlled re-entry is recommended.

Concerning the risks from uncontrolled reentries in general, the last estimates from Carmen Pardini and myself are that currently the global casualty probability is around 2% - 3%  per year. This is the probability that one generic person around the world will be hit in a year by the fragment of a space object that reentered uncontrolled. Approximately 1/3 of the risk comes from satellites, 2/3 of the risk comes from rocket bodies. For any specific individual this risk is still very low, much lower than any other risk we take in everyday life. However, the situation is evolving, due to the changes in space activity, and if appropriate measures are not taken, this risk is bound to grow in the coming years.