It Make some sense to use the Space Shuttle for that, because it could give NRO more flexibility and Reuse of there Optical Systems
So the Idea in begin of 1970s, after dead of MOL.
but KH-11 KENNEN was far better Solution, do it digital equipment making ZEUS obsolete in 1976
Next to that was the Space Shuttle not so flexibility in launching as original planed.
But the Idea of a "Black Spacelab" mission for NRO has something compelling...