KH-11 ("Keyhole-class") spy satellites. It's generally believed that Hubble's optical technology came directly from that. > KH-11s are believed to resemble the

KH-11 ("Keyhole-class") spy satellites. It's generally believed that Hubble's optical technology came directly from that. > KH-11s are believed to resemble the Hubble Space Telescope in size and shape, as the satellites were shipped in similar containers. Their length is believed to be 19.5 meters, with a diameter of up to 3 meters (120 in). A NASA history of the Hubble, in discussing the reasons for switching from a 3-meter main mirror to a 2.4-meter (94 in) design, states: "In addition, changing to a 2.4-meter mirror would lessen fabrication costs by using manufacturing technologies developed for military spy satellites". https://en.wikipedia.org/wiki/KH-11_KENNEN https://en.wikipedia.org/wiki/KH-11_KENNEN