Tohle je klasika. Uspesny biz model vytvori enviro externality, ktere se projevi globalne o 30 let pozdejs. Narodni regulatori povolujou starty tisicu druzic, nikdo za nic nemuze, jsme v tom vsichni, kup vnoucatum investicni opalovaci krem faktor 100 od GoodPhrama, problem solved. Catch me and my profits, if you can, hlupacku.
***
When old satellites fall into Earth's atmosphere and burn up, they leave behind tiny particles of aluminum oxide, which eat away at Earth's protective ozone layer. A new study finds these oxides have increased 8-fold between 2016 and 2022 and will continue to accumulate as the number of low-Earth-orbit satellites increases.
The 1987 Montreal Protocol successfully regulated ozone-damaging CFCs to protect the ozone layer, shrinking the ozone hole over Antarctica with recovery expected in the fifty years. But unanticipated growth of aluminum oxides may delay the ozone success story in decades to come.
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL109280...
MD [molecular dynamics] simulation results show that the byproducts generated tend to rearrange into aluminum oxide clusters and aluminum clusters as the reaction takes place in an oxygen-deficient environment. As a result, aluminum oxide clusters are created after the impingement of oxygen into the original aluminum structure while large clusters of unoxidized aluminum may remain. Furthermore,
we find that these reentry byproducts may take up to 30 years to settle from the top of the mesosphere into the stratospheric ozone layer. Upon reaching an altitude of about 40 km, aluminum oxides catalyze chlorine activation which promotes ozone depletion. This suggests that concentrations of aluminum oxide compounds may start increasing in the mesosphere well before reaching the stratospheric ozone layer. This would introduce a noticeable delay between the beginning of the injection process when orbiting bodies are decommissioned and the eventual ozone-depletion consequences in the stratosphere.For a 250-kg satellite with a 30% aluminum mass fraction at reentry, we find that approximately 32% of the aluminum content gets oxidized, generating 29.8 kg of aluminum oxide clusters. Extrapolating this to the entire population of satellites reentering from LEO in 2022, we estimate that 41.7 metric tons of aluminum reentered the atmosphere, exceeding the natural level from micrometeoroids by 29.5%. Assuming the oxidized material scales linearly with reentered mass, we find that 16.6 metric tons of aluminum oxide compounds are generated from the aluminum influx of spacecraft debris to the mesosphere in 2022. Looking into the future by applying reentry forecasts considering the deployment of mega-constellations, the aluminum excess ratio at the top of the mesosphere can reach an yearly excess of more than 640% above natural levels, or over 360 metric tons of aluminum oxide clusters per year from satellites.
Due to their small size, the byproducts of spacecraft reentry can endure in the atmosphere and remain unnoticed until ozone concentration levels start decreasing. As reentry rates increase, it is crucial to further explore the concerns highlighted in this study. This paper only considered aluminum oxidation due to thermal ablation. The satellite angle of attack during reentry is taken to be constant, thus assuming a controlled reentry profile. Further, the atmospheric model does not account for diffusive or nucleation processes between byproducts. In the simulation, the molecular oxygen number density is taken to be constant due to the short duration of reentry and atomic oxygen is neglected. The MD model does not take into account all chemical species in aluminum alloys and in the air mixture due to the lack of interatomic potentials between such species. These will be addressed in future studies.