A discussion about NIKE ZEUS A started in another thread about a NIKE HERCULES . . . https://www.rocketryforum.com/threads/nike-hercules-two-stage-by-rharshberger.144093 Please check it out to "catch up" to where we are now. I have a "working theory" that I am researching . . . I am theorizing that the Upper Stage of the NIKE ZEUS A might have been the "HERCULES" Upper Stage of the NIKE HERCULES, fitted with the larger fins of the NIKE ZEUS A, and placed atop the THIOKOL MX-135 Booster. NIKE ZEUS A was very short-lived, before being replaced by the NIKE ZEUS B and, later, SPARTAN. During the "gap" in the program, the true purpose of NIKE ZEUS A might have been,essentially, a "Booster Test Vehicle" for the NIKE ZEUS B, to get it "active", until SPARTAN was fully-developed and ready to be deployed. Thoughts ? Dave F.