space at reentry. An important attribute of a layered system of this type includes a provision for downlinking the data from the interceptor sensor as it closes on the target. The in-flight interceptor communication concept is presented in classified Appendix J. This then gives the interceptor a dual role as another layer in the sensor suite, with the most accurate and current data available for use by successive interceptors in the SLS sequence.
In addition to FGA and VAFB, new sites, including a northeastern United States site such as Fort Drum, New York, or northern Maine; a far western site on Shemya, Alaska; and a European site in Poland, were studied. All of these new interceptor sites were assumed to be populated with the new GMD-E high-performance interceptors, as previously described, with communication links to the BMC2 system. In this regard, the first step in a deployment evolution (using GMD-E interceptors) would be a committee-recommended site for 30 interceptors in upstate New York or northern New England. The next step in the evolution would be a phased upgrade of the current interceptors at FGA and VAFB, with the new GMD-E interceptors. In addition, an Aegis system would be used to defend Hawaii (either a ship positioned near Kauai, Hawaii, or Aegis ashore on Kauai with an additional GBX radar and THAAD battery for second shot).
Figures 5-16 and 5-17 and Table 5-3 present hypothetical ICBM threat engagements for scenarios between a Middle East launch point and the East Coast and middle of CONUS. This information is provided as an example of the level of analytical detail that was incorporated within the study process. Similar data
FIGURE 5-16 Example of Middle East to U.S. East Coast four-shot SLS engagement (ground track view).