Penetration aid


A penetration aid is a device or tactic used to increase an intercontinental ballistic missile warhead's chances of penetrating a target's defenses.
These can consist of both physical devices carried within the ICBM, as well as tactics that accompany its launch or flight path, operate as either passive or active counters, and may include one or more of the following concepts:
Carrying such devices has a price in terms of payload weight and volume, which requires a compromise versus warhead size and numbers on board, as well as missile range.