Many geosync orbits trace an asymmetrical 8 on the ground that looks like a keyhole. That's where the name comes from, from programs older than the TK sats.
"The CORONA satellites were designated KH-1, KH-2, KH-3, KH-4, KH-4A and KH-4B. KH stood for "Key Hole" or "Keyhole" (Code number 1010),[7] with the name being an analogy to the act of spying into a person's room by peering through their door's keyhole"
I saw that too but noticed that the claim didn't have a reference. That is what brought me to the NRO PDF, which ties the designation KH of the satellites to the Talent Keyhole security designation on page 15 [0]. One of the confusing parts is that the early Corona didn't have a KH designation initially because the Keyhole compartment wasn't created until 1960 [1]. Maybe the Keyhole compartment's name came from the analogy?
1. In 1960, it was broadened to cover all national aerial reconnaissance (to later include SR-71 sourced imagery) and the KEYHOLE compartment was created for satellite intelligence.https://en.wikipedia.org/wiki/Sensitive_compartmented_inform... compartment%20was%20created
Many geosync orbits trace an asymmetrical 8 on the ground that looks like a keyhole. That's where the name comes from, from programs older than the TK sats.