Upgrades to interceptors and radar are coming. An enemy intercontinental ballistic missile (ICBM) shooting through space as part of a massive nuclear attack can be very difficult for missile defenses to intercept, due to the sheer amount of debris, clutter and specific enemy countermeasures such as decoys intended to confuse or throw off sensors guiding interceptor “kill vehicles.” Several ICBMs can present even more of a problem for defenses, as seekers can at times be at a loss to track multiple threats simultaneously. Moreover, and to perhaps an even greater degree, defenses struggle to distinguish an actual warhead-carrying ICBM from a decoy, debris or even non-lethal parts of the missile breaking off in-flight to release a reentry vehicle.