Rocket launches inject a suite of gases and particulates into multiple layers of the atmosphere, posing threats to Earth’s protective ozone layer, according to researchers from the University of Canterbury (UC) in New Zealand.
They said that rapidly growing aerospace industries could undo decades of work to restore the ozone layer if people don’t start measuring these emissions, assessing their impact on the atmosphere, and designing launches with sustainability in mind, reports Xinhua news agency.
The exact amount and the environmental impact of these emissions are very poorly understood, according to an article published in the Journal of the Royal Society of New Zealand on Friday.
The ozone layer, which protects life on Earth from harmful ultraviolet (UV) rays from the sun, was severely damaged in the 1980s and 1990s due to chlorofluorocarbons (CFCs) – chemicals used in aerosols and refrigeration.
Thanks to coordinated global action and legislation, the ozone layer is now on track to heal this century, the article said.
Rocket launches emit both gases and particulates that damage the ozone layer. Reactive chlorine, black carbon, and nitrogen oxides, among others, are all emitted by contemporary rockets. New fuels like methane are yet to be measured, it said.
“The current impact of rocket launches on the ozone layer is estimated to be small but has the potential to grow as companies and nations scale up their space programs,” said Associate Professor in Environmental Physics Laura Revell.
“Ozone recovery has been a global success story. We want to ensure that future rocket launches continue that sustainable recovery,” Revell said.
Global annual launches grew from 90 to 190 in the past five years, largely in the Northern Hemisphere. The space industry is projected to grow more rapidly, she said.
Rutherford Discovery Fellow and planetary scientist UC senior lecturer Michele Bannister said: “Rockets are a perfect example of a ‘charismatic technology’ — where the promise of what the technology can enable drives deep emotional investment — extending far beyond what the technology also affects.”
Rocket fuel emissions are currently unregulated, both in New Zealand and internationally, Bannister said.
The review article lays out detailed plans of action for companies and for the ozone research community, with a call for coordinated global action to protect the upper atmosphere environment.
Actions that companies can take include measuring the emissions of launch vehicles on the test stand and in situ during flight, making that data available to researchers, and putting effects on ozone into industry best-practice rocket design and development, Bannister said.
Creating sustainable global rocket launches needs coordination across aerospace companies, scientists and governments, she said.