The Hubble Space Telescope is currently out of action, seemingly from a computer-related fault, though booting up the backup computer hasn’t made a difference (so far). In the meantime, here <https://www.theregister.com/2021/06/28/hubbles_cosmic_science_is_mindblowing/> is a retrospective on how that outermost of our sky-seeing eyes came to be, and what it has achieved. Born out of repurposed parts from an unneeded spy satellite? You might think that; those who know couldn’t possibly comment ... By the way, this description of the fault with the mirror And oh yes, that mirror. Younger readers won’t recall the shock at first light when a tiny mistake in its shape made the star of the show useless. Nobody’s saying how many spybirds were similarly afflicted, but where it mattered the most, Hubble was blind. is wrong. Hubble wasn’t blind, it was merely short-sighted. Those pictures that were supposed to have more detail than anything achievable from ground level were only fair-to-middling. I remember a visit to Waikato University in the early 1990s from a researcher in the US who was part of a team that was modelling the blurring effect of the mirror aberration, and applying it in reverse to sharpen up the images to something resembling the quality they were supposed to have. I think they were achieving some useful results. Eventually, of course, their work became unnecessary, as that wonder of eyeglass contraptions called COSTAR was installed.