New Zealand researchers warn that so many rocket launches increase the risk of damage to the ozone layer.
Global annual releases have ranged from 90 to 130 over the last five years, says Dr. Michele Bannister and the University of Canterbury team. “Satellite telecommunications, remote sensing applications, and other scientific and commercial endeavors have spurred the need for providers of space launch and support infrastructure.”, they explain in their new article, published this month in Journal of the Royal Society of New Zealand.
While the cost of deploying reusable rockets is falling, making launches more frequent and common, these rocket launches come at a cost to the health of Earth’s stratosphere.
Currently, the industry relies on four main types of rocket fuel: liquid, cryogenic, hypergolic and solid kerosene. When rockets are launched with these propellants, the result is a mixture of gaseous and particulate emissions that include carbon dioxide, black carbon, nitrogen oxides and other substances.
Rocket launches and their impact on the ozone layer
Not much is known yet about the impacts of rocket launches on the ozone layer, 90% of which is in the stratosphere layer of the atmosphere, between 15 and 50 kilometers (km) above the Earth’s surface. However, some estimates suggest that two-thirds of all rocket launch emissions are injected at a level above 15 km. There is a possibility that they will remain present longer at this atmospheric height, causing harmful impacts even in relatively small numbers.
The Canterbury scientists point out that protecting the ozone layer has been a global environmental success story since the implementation of the Montreal Protocol reduced chlorofluorocarbon damage caused by solvents and refrigerants and with reductions in methane emissions. However, these gains could be reversed with routine rocket launches, especially as the industry explores new emerging methane fuels.
New engines for rocket launches
“Many rocket engines currently in development have turned to methane fuel, including SpaceX’s Starship, Rocketlab’s Neutron and ESA’s Ariane Next Arianespace.the authors said. “Until now, the products of methane fuel emissions are not well understood and not experimentally quantified.“.
Bannister and his colleagues see the aspirational power of rocket deployment, but they also see the charismatic quality of space technology. He often limits any challenge to utopian promises about the future of space exploration and its applications.
“That storytelling power can level the potential for a subtle discussion about how rockets can best be forged into the tools we’d like to have to achieve certain outcomes, from solar system-wide exploration to a thriving near-Earth space economy.”, said the scientists.
Protect the upper atmosphere
Communications, space tourism initiatives and even future navigation technologies will only drive demand for the sector. So they call for coordinated global action to protect the upper atmosphere, with companies tracking emissions and making the data available to ozone researchers for optimal rocket design.
“Creating sustainable global rocket launches will require coordination from aerospace companies, scientists and governments: it’s possible, but we must start nowsays Banister. “This is our chance to stay ahead of the game.”.
