Thousands of satellites are currently parked in low Earth orbit, with some eventually disintegrating and falling back into our planet’s atmosphere. When satellites re-enter the atmosphere, they leave behind a trail of chemicals that eat away at the ozone layer. A new study warns that the growing number of internet satellites has contributed to a shocking eight-fold increase in harmful oxides in the Earth’s atmosphere over six years.
Not all satellites are created equal. Internet satellites tend to have a shorter lifespan of around five years, after which they are it flew out of orbit and descended towards the earth’s atmosphere. Of the nearly 10,000 satellites in orbit today, two-thirds belong to SpaceX’s broadband constellation, Starlink.
SpaceX has launched more than 6,000 Starlink satellites into orbit, and the company’s founder, billionaire Elon Musk, hopes to build a massive constellation of 42,000 satellites. SpaceX isn’t the only company building constellations in low Earth orbit. Project Kuiper by Blue Origin also plans to send 3,000 satellites into space, while Europe’s OneWeb wants to build a constellation of 648 satellites. These numbers cause us with Kessler syndrome great anxiety.
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In addition to the increased risk of collision, Internet satellites rotate more frequently than their longer-term counterparts, with companies repeatedly introducing replacements to maintain their broadband services. At the end of their short lives, satellites generate pollutants as they fall through the atmosphere. Satellite reentry produces tiny particles of aluminum oxide that trigger chemical reactions that destroy stratospheric ozone, according to a recent studies published in Geophysical Research Letters. The oxides do not react chemically with ozone layer molecules; instead, they trigger destructive reactions between ozone and chlorine that end up depleting the protective layer in the Earth’s atmosphere.
“It’s only been in recent years that people have started to think that this might be a problem,” said Joseph Wang, an aerospace researcher at the University of Southern California and lead author of the new study. declaration. “We were one of the first teams to look at the implications of these facts.”
Using a model of the chemical composition of the material used to make satellites, the researchers found that a typical 550-pound (250-kilogram) satellite, with aluminum making up 30% of its weight, would generate about 66 pounds (30 kilograms). of aluminum oxide nanoparticles (1 to 100 nanometers in size) during its re-dip. Based on this modelling, the study revealed that returning satellites increased the amount of aluminum in the atmosphere by 29.5% over natural levels from 2016 to 2022.
It only gets worse from there. According to the study, it would take about 30 years for aluminum oxide particles to reach the same height as the Earth’s stratosphere, where 90% of ozone is found. Before the planned Internet constellations are built in low Earth orbit, 1005 tons of aluminum will fall into the Earth’s stratosphere. This releases approximately 397 tons of aluminum oxides into the atmosphere annually, an increase of 646% over natural levels.
Just when things started looking up for the Earth’s ozone layer. A recent assessment by the United Nations Environment Program revealed that the ozone layer is on track for complete recovery by 2066. Almost 99% of ozone depleting chemicals have been phased out since the 1980s thanks to the international treaty to protect our ozone signed in 1987.
A recent study highlights the need for better regulations to help mitigate the effects of a growing space industry — one that loves to deploy satellites around the Earth.
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