missile was the second US Navy ballistic missile
system, powered by a two-stage solid fuel rocket. It succeeded the Polaris missile
beginning in 1972
, bringing major advances in warheads and accuracy. It was followed by Trident
I in 1979
, and Trident II in 1990
Poseidon, although longer and considerably heavier than Polaris A-3, had the same 4600 km (2500 nautical mile) range. It also had improved accuracy and up to 14 W68 multiple independently targetable reentry vehicles (MIRV) in its warhead bus.