SEU results from the Advanced Photovoltaic and Electronics eXperiments (APEX) satellite

The APEX satellite, launched in August of 1994, had a solid state data recorder (SSDR) as its onboard data storage system. The recorder contained 220 4Mbit/spl times/1 Hitachi DRAMs of which 176 were routinely interrogated for SEUs and corrected with an EDAC code. Corrections were recorded in the spacecraft housekeeping files and are the basis of this study. The SEU rates and spatial locations are compared to in situ particle measurements and to ground test results from devices from the same lot flown. The results show that properly designed SSDRs are a viable alternative to conventional tape recording systems for all orbits in near-Earth space.