Space Debris: Is It a Crisis?

I heard StarLink satellites eventually re-enter the atmosphere when they are not orbit-stable. Thus this technology is bad for life on earth when it is lauched into space and again when decommissioned.

Here an article on that:

https://www.cnet.com/home/internet/are-starlinks-satellites-...

Quite a crazy example of how costs are externalized, while profits are accumulated at the top.

Why is it bad ? Like compared to lets say a car or any number of industrial products ?

Satellites comprised mainly of aluminium burn up in the upper atmosphere. This likely reduces the ozone layer, as that's where the chemical reactions take place, unlike industrial activity on the ground. A certain amount of aluminium gets injected into the upper atmosphere by meteorites without any human activity involved, but the quantities burned up by modern satellite constellations will significantly exceed that. Nothing different about Starlink satellites compared with anyone else's operating in LEO, but they do operate more than anyone else.

> I heard StarLink satellites eventually re-enter the atmosphere when they are not orbit-stable. Thus this technology is bad for life on earth when it is lauched into space and again when decommissioned.

The fact that they re-enter by itself is not the problem. The problem is that they contain aluminium:

> When Starlink’s satellites reach the end of their lives, they burn up in the Earth’s atmosphere and leave behind small particles of aluminum oxide. These travel down into the ozone layer, which absorbs harmful ultraviolet radiation. Researchers from the University of Southern California found that these oxides have increased eightfold from 2016 to 2022.

Why are we comparing it to other things that also have negative ecological consequences? Cars also being bad for the environment doesn't make ozone-depleating space-litter any better

There's considerably more aluminum oxides in the stratosphere from solid rocket motors than satellite reentires, and that's been going on since the 1970's. The 135 Space Shuttle launches burned 160 tons of aluminum powder, per launch, in their SRB's. (22 kilotons in total?) An Ariane 6 launch burns 55 or 110 tons (2 or 4 boosters).

The largest satellite payloads are 20 tons in a launch.

(Al2O3 isn't even the highest-impact ozone depletor within the space industry; that's chlorine. Also from solid rocket fuel).

> University of Southern California found that these oxides have increased eightfold from 2016 to 2022.

DOGE about to cancel funding for USC

Yes, I agree launches also contribute and increase frequency is also a plausible risk factor (and is significant increases in launch frequency themselves driven by megaconstellations, though I don't think the Falcon 9 is as problematic as the Shuttle was) Main difference is that the satellites lose most of their mass in the relevant zone, whereas launches pass through it as quickly as possible. Satellites are small, but Starlink's deorbiting cycle is expected to reach 2 tonnes per day.

USC is already rescinding PhD offers due to federal funding that got pulled

I hate this timeline