KH-11s were optical telescopes aimed at planet earth. To my eyes, they look exactly like the Hubble telescope, just pointed the other way. But there have also

KH-11s were optical telescopes aimed at planet earth. To my eyes, they look exactly like the Hubble telescope, just pointed the other way. But there have also been lines of satellites created for doing radio captures, also pointed down. See https://en.wikipedia.org/wiki/KH-11_KENNEN https://en.wikipedia.org/wiki/KH-11_KENNEN and https://en.wikipedia.org/wiki/Aquacade_(satellite) https://en.wikipedia.org/wiki/Aquacade_(satellite)