A @Nature paper published today argues that "Satellite megaconstellations will threaten space-based astronomy" https://www.nature.com/articles/s41586-025-09759-5
Here's the punchline of the paper: satellites could be a problem even for orbiting space telescopes, but the impact depends on how many are launched. "Our results show that if these constellations are completed, one-third of the images of the Hubble Space Telescope will be contaminated, while the SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer), ARRAKIHS (Analysis of Resolved Remnants of Accreted galaxies as a Key Instrument for Halo Surveys) and Xuntian space telescopes will have more than 96% of +0.3 their exposures affected, with 5.6^+0.3_−0.3, 69^+21_−22, and 92^+11_−10 trails per exposure, respectively, with an average surface brightness of μ = 19 ± 2 mag arcsec−2."
