Chevaline's penetration aids and the cost in range

Chevaline carried two hardened warheads, one remaining on the missile and the other on a manoeuvring penetration-aid carrier. That carrier also deployed decoys, and the arrangement differed from a later bus dispensing multiple independently targeted re-entry vehicles. The two warheads could reportedly strike as much as 40 kilometres apart. The heavier package reduced Polaris's maximum range and constrained the submarine's operating area. Its decoys, reportedly numbering 27, included heavy objects with thrusters and lightweight objects that slowed more rapidly in the atmosphere. Outside the atmosphere, similar radar returns made lightweight decoys difficult to distinguish from warheads. An interceptor operating inside the atmosphere could exploit their different drag, while heavier decoys remained a problem. Soviet work on such an interceptor therefore increased the attraction of missiles with many more warheads, preferably independently manoeuvring.