Space testing of LSI memories

LSI memory soft error was tested in space on 64K-bit Dynamic RAM (n MOS), 16K-bit Static RAM (n MOS), and 1K-bit Static RAM (C MOS), using a sounding rocket. These LSIs had a 161 kbyte memory capacity. The test data ('1' or '0') were written and read out cyclically, and compared with the original data. If bit error was detected, error data were transmitted by telemetry. Vibration and thermal vacuum tests led to the conclusion that the LSI test equipment sufficiently satisfied the requirements to be loaded on the sounding rocket. No error was observed during the flight. LSI memories were not influenced by the launch environment or cosmic rays. Analytical results of the flight data are also discussed in this paper.