The first drafts for a large space telescope such as Hubble were made in the 60's, and the idea of a space observatory originated long before that. From Wikipedia:

In 1968, NASA developed firm plans for a space-based reflecting telescope with a mirror 3 m (9.8 ft) in diameter, known provisionally as the Large Orbiting Telescope or Large Space Telescope (LST)

Back then, CCDs weren't a thing yet (W. S. Boyle; G. E. Smith (April 1970). "Charge Coupled Semiconductor Devices". Bell Syst. Tech. J. 49 (4): 587–593.), and observational astronomy relied on photographic plates. How was the data meant to be collected and sent back to Earth in these projects?

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    $\begingroup$ Photomultiplier tubes (with and without image intensifiers), Microchannel plates for the UV (a big advantage of going to space) and Reticon arrays (for spectroscopy) were all used for astronomy before CCDs and would have produced digital (or digitizable) signals that could have been transmitted to the ground. $\endgroup$ Jan 29, 2020 at 16:29
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    $\begingroup$ I was hoping the answer would be something cool like sending astronauts to switch the photographic plates... $\endgroup$
    – usernumber
    Jan 29, 2020 at 16:32
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    $\begingroup$ Well the early spy satellites did drop film canisters out to be caught by planes with hooks, don't know if this was ever envisioned for the space astronomical telescopes. Mainly I wanted to point that there was (astronomical) life before CCDs and after photographic plates (which were still in use for surveys until relatively recently) $\endgroup$ Jan 29, 2020 at 16:36


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