The space race that is seeing SpaceX, Eutelsat and Amazon launch thousands of satellites capable of providing internet service will probably carry a significant environmental cost. That is what the first attempt to calculate the carbon footprints associated with each company’s operations has concluded.
The analysis, conducted by researchers in the US and UK, found that the carbon footprint of each satellite constellation is potentially 14 to 21 times higher per internet subscriber than the emissions associated with land-based mobile internet – primarily because of rocket launch emissions like carbon dioxide and carbon monoxide.
What’s more, the polluting potential of satellite internet services may actually be much higher than this initial calculation. When the study authors considered the possible impacts of additional rocket launch particles – such as black carbon, aluminium oxide and water vapour exhaust – they calculated that the carbon footprint per subscriber might rise to between 31 and 91 times that of a land-based internet option.
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Among the three satellite internet competitors, SpaceX’s Starlink generally manages to achieve the lowest carbon emissions per internet subscriber – about 31 times larger than terrestrial equivalents – primarily because it serves the largest number of customers, meaning the emissions per user are lower.
Amazon’s upcoming Project Kuiper constellation may deliver the worst emissions impact of the three, partly because it is expected to use Europe’s new Ariane 6 rocket system for many of its launches. Unlike the SpaceX Falcon 9 rocket used by Starlink and by Eutelsat’s OneWeb satellites, the Ariane 6 rocket system will use solid fuel propellant that emits significantly higher amounts of certain particles, such as aluminium oxide.
The study takes “a big first step” in accounting for the most immediate emissions impact from launching satellite constellations, says at the Aerospace Corporation, a space-focused non-profit in California, who was not involved in the research. But he points out that this emissions impact will change in the years ahead. In particular, the satellites are designed to burn up in the Earth’s atmosphere after four or five years, at which point new replacement satellites will have to be launched – and the carbon footprint of the service will grow even more.
“One of the characteristics of the spaceflight industry is that we don’t have a history of looking at global impacts,” says Ross. “It’s a fairly young industry, and it’s been largely unregulated.”
arXiv
