Inventory Counts Air Pollution Cost of Space Launches and Re-Entries

An anonymous reader quotes a report from The Guardian: A new global inventory has catalogued air pollution from space activities from 2020 to 2022. The inventory includes time, position and pollution from 446 launchers as they ascended and the tracks of re-entries as objects are heated to extreme temperatures and break up or burn up in the upper atmosphere. It catalogues the pollution from 63,000 tons of rocket propellants used in 2022 and from 3,622 objects, including rocket parts and satellites, that re-entered the atmosphere between 2020 and 2023, amounting to about 12,000 tons.

Types of launch pollutants depend on the propellent but can include particles of soot and aluminum oxides as well as nitrogen oxides, chlorine and water vapour and carbon dioxide. Extreme heat on re-entry causes atmospheric oxygen and nitrogen to combine to form more nitrogen oxides and also produces tiny metal-oxide particles as the objects break and burn up. Soot emitted high in the atmosphere can persist for several years, with a resulting climate warming impact that is up to 500 times greater than the same amount of soot from aviation or ground-level sources. Aluminum oxide particles, nitrogen oxides and chloride can consume the ozone in the stratosphere that protects us from the sun's ultraviolet radiation. These can remain in the atmosphere for decades. Dr Connor Barker, of the UCL team, said: 'Many rocket manufacturers and space agencies keep this information tightly controlled. We had to be creative about the different sources we consulted, from launch live streams on YouTube to online databases maintained by space enthusiasts in their spare time.'

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