sauce: the future of the earth
The space industry is experiencing rapid growth. Over the next few years, nearly 10,000 spacecraft are scheduled to be launched into low-Earth orbit for a variety of purposes, including “megaconstellations” of satellites providing global surveillance, space travel, and Internet services.
Rocket engine exhaust, as well as the combustion of inactive satellites and rocket parts that re-enter Earth’s atmosphere, release an array of pollutants. Given the historically small size of the space industry, these chemicals have long been thought to pose little threat to the climate. Now, with the sector’s rapid growth, its emissions will skyrocket, but scientists still don’t have a clear picture of the environmental impact.
analysis by Vliex et al. The number of rockets launched in 2022 reveals that spaceflight is depleting the ozone layer and contributing to global warming. A significant portion of this ozone loss is due to nitrogen oxide emissions released by objects re-entering the Earth’s atmosphere.
The researchers calculated emissions from all 186 rockets launched in 2022 and all 472 objects (with a total mass of about 5,000 tons) that reentered the atmosphere that year. They conducted computational simulations of the trajectory and emissions of each launch at various altitudes up to 100 kilometers and calculated the emissions emitted by object re-entry. They also considered the effects of chemical reactions that occur in the rocket’s exhaust plume and change the chemical composition of the exhaust.
Incorporating the calculated emissions into GEOS-Chem, a computational model for atmospheric chemistry, revealed the impact on ozone layer depletion and global warming, identifying reentry emissions as playing an important role in ozone depletion. The researchers found that accounting for plume reactions reduced the estimated impact of spaceflight emissions, highlighting the value of considering plume chemistry in future assessments.
The analysis also highlighted that different types of rocket fuel have different impacts. The solid fuel recently used in rocket boosters for NASA’s Artemis II mission to return astronauts to the moon is thought to cause the most amount of ozone depletion relative to its mass of propellant, while rocket-grade kerosene is thought to cause the most amount of warming.
Based on their findings, the researchers call for further research into the chemistry of reentry emissions and rocket plumes as the space industry continues to expand and evolve. (the future of the earthhttps://doi.org/10.1029/2025EF007795, 2026)
—Sarah Stanley, science writer
