Planned satellite megaconstellations could generate runaway space debris
By Hannah Richter, Science.
Excerpt: Sixteen thousand satellites currently whiz above our heads on a 3D space superhighway. ...that number may increase 10-fold within the next decade as operators launch internet and telecoms satellites en masse. ...A new analysis posted to the preprint server arXiv last week, however, suggests those plans face a physical limit, stemming not from the number of satellites, but from the space junk generated as they collide. The study finds that the swarms of satellites, known as constellations, would reach a threshold known as Kessler syndrome ...proposed in 1978 by NASA astrophysicist Donald Kessler, describes ...collisions between spacecraft produc[ing] space junk faster than what falls naturally out of the atmosphere because of drag. ...that leads to an exponentially increasing amount of debris, posing threats to other satellites, limiting safe launch windows for future spacecraft and astronauts, and jeopardizing human infrastructure when the debris falls back to Earth. ...Of the 16 planned constellations, comprising nearly 1.7 million satellites, six passed the threshold into runaway debris, among them China’s Guowang, Cowboy Space Corp.’s Stampede, and Blue Origin’s Project Sunrise. Perhaps the most notable generator of debris would be Starmind, SpaceX’s plan for 1 million satellites to act as orbital data centers....