::Would it not be worth adding a comment that they all have (or are thought to have) a primary mirror of a similar size, and it is rumoured that their overall size, shape and design is believed to be quite similar (they are, after all, all 2.3/2.4 metre space telescopes, so they all ought to be pretty similar). KH-11 currently says "NASA's Hubble Space Telescope is rumored to be a derivative of the KH-11, though with different instrumentation, sensitivity levels, and a vastly different focal range. The two were supposedly transported in the same shipping container, lending credence to the speculation."  and KH-12 says "Like the KH-11 (Crystal), the KH-12 is believed to use a large mirror to capture light, and probably resembles the Hubble Space Telescope (HST) in size and shape."  (although it also says that the primary could be up to 4m, which seems rather unlikely to me). At the very least, we ought to mention rumours that they are all similar.