“Over the past half century, the world has sent all manner of satellites up into space — spy satellites, GPS satellites, weather satellites and more — nearly 15,000 in all. SpaceX has launched two-thirds of those, which power its Starlink internet service.”
“The million or so more that SpaceX is proposing would be used as data centers for artificial intelligence”
“Google’s Project Suncatcher is developing orbiting data center technology. Jeff Bezos, who owns the space company Blue Origin, has said he’s interested in similar efforts. And last year, China began launching AI-computing satellites that it hopes will eventually number in the thousands”
“According to a research paper published in Nature Sustainability last year, climate change is expected to sharply reduce the room available for satellites in some particularly useful and in-demand orbits”
“the greenhouse gases that are warming the planet, like carbon dioxide, are also causing the upper atmosphere to cool and contract, making the already extremely thin air up there even thinner. That’s bad news for satellite orbits because the drag from the thin air in the upper atmosphere is what helps force objects back down toward Earth”
“it acts as a cleaning mechanism, over time removing dead satellites and other space junk that would otherwise stay there, clogging up orbits. The objects largely burn up as they re-enter Earth’s lower atmosphere”
““So we’re losing this cleaning force that we rely on,” said William Parker, a scientist at The Aerospace Corporation, which conducts research and development for U.S. space programs, who led the study while at the Massachusetts Institute of Technology. There is currently no other way to remove large amounts of space junk or decommission satellites, he said. (Other scientists are studying the environmental issues with this method, like pollution from incinerated metals and the risk of falling fragments.)”
“The vast majority of satellites operate between roughly 250 and 620 miles above Earth. By the end of the century, the study estimates this zone will be able to safely hold fewer than 150,000 typical satellites, or only about half as many as today”
“scientists fear a runaway chain reaction that gradually fills Earth orbit with shrapnel, rendering it too dangerous to use”
“That possibility even has a name: the Kessler syndrome, named after one of the scientists who first proposed it. It’s a worst-case scenario, but considered serious enough that it is studied by researchers”
“Some operators hope dead satellites might eventually be towed into even higher altitudes, where so-called a graveyard orbit is thought to be able to hold objects for millenniums. But this feat has been achieved only once, by China”