Basically, the later versions with smaller radome and antenna were able to have the same or better resolution by advances in antenna design & construction and improvements in signal-processing circuits (as well as in the components of those circuits).

They just didn’t need that large set-up to do what they needed to.

I expect that the fabric of the inflatable cover was also not as durable as required, the antenna folding mechanism was a problem (jamming in place, etc), and the added weight/volume of the inflating equipment, etc was detrimental to payload/range performance.

HOw ’bout we tried this cover today, with modern fabrics. We still need something to put on the V22, EH01 and old S2 Trackers….