Figure 2: Average Number of Available Interceptors by Latitude for 100, 500, 1000, and 1500 Interceptor Constellations. Each constellation is modeled with a 45-degree inclination using interceptor parameters from the American Physical Society’s 2004 Study Group on Boost-Phase Intercept Systems for National Missile Defense. A response time of 170 seconds is used, corresponding to liquid-fueled missiles, like those tested by Iran and North Korea. Source: CSIS Aerospace Security.