Comment by Retric

“A Starlink satellite has a lifespan of approximately five years” https://www.space.com/spacex-starlink-satellites.html

A 5 years useful lifespan sets the replacement rate and thus the average number burning up each year. In steady state the delta between end of life and reentry is irrelevant, instead the average number of satellites launched each year = average number that burn up each year.

As to harm. Aluminum is mildly toxic, you don’t eat your bike but vaporized aluminum from a satellite is way more likely to cause harm than if the things were made of steel. The plastic bits are likely fine though.

Saying let’s study something ahead of time rather than contaminating all the world’s farmland with and then seeing what happens seems like a perfectly reasonable standard. Technology has generally been wonderful, but that doesn’t mean everything is equivalent. We want to phase out leaded aviation fuel in the US even though it’s ‘only’ 2,000 tons of lead per year, that’s still enough to be problematic. Perhaps ramping up to ~5k tons/y of vaporized aluminum worldwide is a complete non issue, but if it’s not insisting on some other material isn’t the same as a ban.