Article says Snark was killed by the land-based, liquid fueled Atlas ICBM, but the Polaris submerged-launched ICBM Is what probably what did it in. The first submerged launch was July 1960. snark was ended by Kennedy in 1961.
My Dad was a key player in the Polaris guidance system development at GE.
The Polaris going on line, as well as reliable ICBM’s, is why Kennedy was looking to phase out the PGM-19 Jupiter before the Cuban Missile Crisis. The Jupiter was also a stopgap, as well as obsolete shortly after it was deployed.