"Killer electrons," enhanced fluxes of radiation belt electrons in the magnetosphere-especially those at geosynchronous orbit (GEO)-were an important space weather phenomenon during the decline to minimum of the last 11-year solar cycle (1993--1995). Indeed, the fluxes of these electrons were reported at the time to have significantly influenced the incidence of anomalies on numerous spacecraft, both commercial and national defense. The incidences of spacecraft anomalies and the "pumping up" of the GEO electron fluxes gave rise to the picture that solar minimum did not provide a benign environment for space-based technologies as had been assumed by many.