The KH-6 LANYARD was part of the Keyhole series of IMINT satellites. It was a film camera design, and produced stereoscopic imagery. The KH-6 flew one successful mission in 1963.
Imagery from the LANYARD program, along with that from the KH-5 ARGON and KH-1 thru KH-4 CORONA, was recently declassified and made available to the public.