Complex sentence: The KM was designed in 19641965 in the closed, military city of Nizhniy Novgorod, and was unique in size and payload The first spy photographs from American spy satellites showed a strange aircraft carrying letters "KM" on its fuselage.
Split into simpler sentences: The KM was designed in 19641965, and was unique in size and payload. It was built in secrecy at the military city of Nizhniy Novgorod/The first spy photographs from American spy satellites showed a strange aircraft carrying letters "KM" on its fuselage.