Identification of an unexpected space radiation hazard

A new radiation belt was formed on 24 March 1991 by the interaction of a strong shock in the solar wind with the Earth´s magnetosphere. The authors describe observations of the moment of creation by sensors aboard the CRRES (Combined Release and Radiation Effects Satellite). The electrons and protons injected into the magnetosphere in this event are highly penetrating and represent a threat to spacecraft orbiting in that region of near-Earth space. It is pointed out that the injection event was completely unexpected and may have been a unique occurrence in magnitude during 35 years of space research. However, the response of the early particle sensors to such an event is not obvious, and therefore a definitive conclusion is difficult to make