It's neat when you live long enough to see some of these long-gestating babies grow up and do their thing. I'm hoping the same for one I've worked on.
NASA definitely learned a few things from Perkin-Elmer's mirror mistake on the Hubble Space Telescope:
Hubble's primary mirror was built by what was then called Perkin-Elmer Corporation, in Danbury, Connecticut. Once Hubble began returning images that were less clear than expected, NASA undertook an investigation to diagnose the problem. Ultimately the problem was traced to miscalibrated equipment during the mirror's manufacture. The result was a mirror with an aberration one-50th the thickness of a human hair, in the grinding of the mirror.
Replacing the mirror was not practical, so the best solution was to build replacement instruments that fixed the flaw much the same way a pair of glasses correct the vision of a near-sighted person. The corrective optics and new instruments were built and installed on Hubble by spacewalking astronauts during a shuttle mission in 1993. The Corrective Optics Space Telescope Axial Replacement (COSTAR) instrument, about the size of a telephone booth, placed into Hubble five pairs of corrective mirrors that countered the effects of the flaw.
https://www.nasa.gov/content/hubbles-mirror-flaw