The Navy would have used it for aerial surveillance most likely - no focusing required, it would have always been shot at infinity. It would have been mounted to a fixed position aimed out a window. Probably also used for night-time surveillance. And compared to the optics used to photograph high resolution terrestrial images from space, that lens would probably have been cheap.
Cheap for a branch of government that I watched push perfectly good helicopters into the ocean to save deck space. The military probably taught budgeting to the NSA.
I photograph things to see what things look like photographed.
- Garry Winogrand