In 2019 SpaceX began deploying a constellation of internet relay satellites called Starlink. The satellites are relatively large (about 3m flat-panel bus with 9m solar array) and in low (300-550 km) orbits, and in their initial design are unexpectedly bright naked-eye objects. Various proposals filed with the FCC described constellations of 4000, 12000 and ultimately 30,000 satellites. Widespread optical observations of the satellites raised the concern that the fully deployed constellation would have severe impacts on astronomical observations and even on appreciation of the night sky by ordinary people around the world.
In early 2020 the various filings represented a proposed 12000 satellite constellation. I discussed the effects of such a constellation in a paper in the Astrophysical Journal Letters:
By late May 2020, however, Starlink had updated its plans - partly in response to the concerns of astronomers. On this web page I will present updated simulations.