The behaviour of measured SEU at low altitude during periods of high solar activity (spacecraft memories)

The UoSAT-2 spacecraft, launched in 1984 into a polar orbit at an altitude of 700 km, has a number of systems which have been observed to experience single-event upsets at significant rates. During the year 1989, several solar flare events occurred which elevated the upset rates at high latitudes. The October 19 event, in particular, resulted in very high high-latitude upset rates. The data are separated and analyzed, deriving upset rates for the various memory devices under quiet cosmic-ray, South Atlantic anomaly, and solar flare conditions. The results of the heavy ion and proton testing of UoSAT memories undertaken in order to compare predictions and observations are presented.<
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