How bad for the planet is satellite broadband?
This latest, faster generation of satellite broadband might bring a smile to the face of people who were stuck on dismally slow connections, but it’s not pleasing everyone. Not least those who are worried about its impact on the planet and the sky above.
On a clear night, you might be able to see Starlink satellites passing overhead with the naked eye – the light reflects off them to give the appearance of a shooting star. The satellites are unmissable if you take photos of the night sky, however.
The photo shown here was taken by the University of Calgary’s Rothney Observatory and shows a set of 60-second exposures, taken over two hours, stacked upon one another. As the accompanying tweet from the observatory’s twitter account (@RAOastronomy) notes, “the astronomical wonders appear to get lost behind the web of satellite trails”.
Then we come to the environmental impact. As impressive as it is to see batches of 60 satellites being launched with almost monotonous regularity, every two to three weeks, questions are being asked about its impact on both Earth and space.
When Starlink asked for permission to lower the orbital altitude of its satellite constellation in January, Amazon objected on the grounds that it raised the risk of devastating collisions, potentially leaving a massive field of debris scattered in lowearth orbit. The so-called Kessler syndrome, where pieces of space debris cascade into each other, is a very real threat if the satellites come into contact with one another.
Starlink will eventually dispose of its satellites by lowering their altitude to a point where they burn up in the atmosphere, but that process has also raised concerns. Rival Viasat called for the US Federal
Communications Commission (FCC) to carry out an environmental impact study, citing research from
The Aerospace Corporation that argued that the burnt-up satellites would produce aluminium oxide, which contributes to climate change. In a spiky riposte to Viasat’s complaints, Elon Musk tweeted: “Starlink poses a hazard to Viasat’s profits, more like it.” He didn’t address the environmental concerns.
Let’s also not forget the environmental impact of the launches themselves. Starlink satellites are launched aboard a SpaceX Falcon 9 Block 5 launch vehicle, which at least is partially reusable. The first-stage boosters are expected to be launched at least ten times with minor repairs, and potentially up to 100 times with refurbishment.
What isn’t recycled, of course, is the fuel. The firststage boosters can take up to 287,400kg of subcooled liquid oxygen and 123,500kg of kerosene. The second stage uses about a quarter as much again.
Then, finally, there’s the power consumption of the Starlink equipment. Your average broadband router will consume only a few watts of electricity. Not so Starlink. A report on ISPreview.co.uk shows that the receiving equipment consumes around 89W when idle and around 110W during normal operation, occasionally peaking at 175W when the motorised dish is trying to latch onto satellites. That’s not only bad for the environment, but bad for your electricity bill, with ISPreview.co.uk pinning the annual electricity cost at around £160.