EndoExoatmospheric Interceptor (E2I)
EndoExoatmospheric Interceptor (E2I) : A ground-based interceptor capable of engaging RVs either endoatmospheric or exoatmospheric. (Successor to High Endoatmospheric Defense Interceptor (HEDI).) Endoatmospheric Within the earth's atmosphere; generally considered to be altitudes below 100 km. An endoatmospheric interceptor reaches its target within the atmosphere