Dfense Support Program Three Dcades on Wotch The Northrop Grumman-built D驩fense Support Program (DSP) satellites have been the spaceborne segment of the nation's early warning System since 1970. Using infrared detectors that sens the heat from missile plumes against the earth back-ground, thse orbiting sentries detect, characterize and report ballistic missile launches; they o/so see nuclear d騩tonations. Continuous spacecraft upgrades have allowed DSP to provide accurate, reliable warning data in the lace of changing requirements with no interruption in service. Planned evolution-ary growth has...