Does this create pollution? I don't think I want to inhale satellite dust.
So basically it's not worth worrying about.
1. https://en.wikipedia.org/wiki/Starlink#v2_(initial_deploymen...
Vaporized satellites really don't seem like a concern.
1. https://en.wikipedia.org/wiki/Dichlorodifluoromethane#Enviro...
The first is that IIUC, CFCs release chlorine atoms which catalyze ozone, whereas aluminium oxide catalyzes the creation of chlorine atoms from chlorine reservoirs, which then go on to catalyze ozone. I loosely believe at this point after some sketchy research and maths that this makes it around two orders of magnitude more potent.
The second is that these particles are produced directly in the upper atmosphere. I couldn't give you a number for how much that changes things, but I assume it's nontrivial.
The final point I've noticed is that mass to orbit has been increasing at a rapid exponential rate recently, and it would not surprise me at all to soon see an extra order of magnitude on it.
Worst-case, that could change your 5,000 year figure to just a couple. I don't think it's that bad, I'm not overly concerned about this issue, but given ozone depletion is a legitimate existential threat and the numbers don't immediately make it seem impossible, I think it's worth paying attention to.
My point is, Starlink is doing this now, but they are continuing to scale up. Other companies are going to follow. Is there a point that this does become something to worry about because the scale has increased?
If the reentering satellites were somehow transformed entirely into chlorine gas that somehow stayed in the atmosphere forever, we would reach the OSHA permissible exposure limit of 1ppm after 250 years. Chlorine is detectable by smell at 3ppm, which would take 750 years.
It's very likely that the vast majority of the vaporized satellites are inert, as they are basically incinerated on reentry. It's also likely that most of of the vaporized satellite does not stay in the atmosphere for very long. The only way this could be a problem is if the satellites emit a long-lived compound that catalyzes a reaction in the atmosphere, similar to how CFCs destroy the ozone layer. So far, the only candidate for that is aluminum oxide particles, and solid rocket boosters create more of that than reentering satellites. (Fortunately aluminum oxide isn't nearly as bad for the ozone layer as CFCs, and SpaceX does not use solid boosters.)
Also once you are launching tens of thousands of tons to orbit per year, it starts to become feasible to build infrastructure in space. Satellites at the end of their service life contain valuable raw materials. It would likely become cheaper to refurbish or recycle them rather than deorbit and launch new ones.
But, it WILL affect things in climate and atmosphere.
https://csl.noaa.gov/news/2025/427_0428.html
"Pollution" is what this is
Kerosene rockets produce soot. Methalox rockets (like Starship) produce plain CO2 and water.
There are high-atmosphere effects we don't yet understand. RP-1 produces soot, particularly when burned fuel rich. And methalox still releases methane since again you're not burning your fuel perfectly.
But the simplicity of non-hypergolic non-kerosene rocket fuel chemistries like the ones SpaceX uses is they burn remarkably clean. You don't get a bunch of additives producing weird neurotoxins, or incomplete combustion inventing organic compounds in the high atmosphere.
(I'm ignoring cryogenic fuels, which literally produce water vapour as an exhaust because liquid hydrogen is a bastard.)
> As in, we could launch a million rockets per day with a negligible effect on the air and other environments?
No. Starship releases like 360 tons of CO2 per launch [1].
That said, nobody is launching a million rockets a day. We might get to like 3 or 4 a day in our lifetimes. Barring some novel economic opportunity in space, launch emissions are likely to remain negligble for the foreseeable future.
[1] https://www.theecoexperts.co.uk/news/elon-musk-rocket-emitte...