Use of non-radiation hardened micro-circuits in space — Experience from the cluster digital wave processor Original Research Article

The trend for higher performance, lower cost, space instrumentation is leading towards the use commercial or industrial electronic parts, rather than specifically radiation hardened military grade parts. The micro-processor and memory devices used in the Cluster Digital Wave Processor (DWP) are not specifically radiation hardened parts, although they were selected to withstand the expected total dose radiation. The hardware includes current limiting to protect against the damaging effects of latchup, and a watchdog to reset the processor in the event of incorrect operation. Resources did not permit the use of hardware error detection and correction (EDAC) of single event upset (bit errors) in memory, so software techniques are used to protect against memory errors. We present the experience of the first two years of operation of the Cluster mission, reporting on the observed rate of single event upset and latchup in the DWP, and the resulting impact on science observations. Overall the results have been good with very little loss of science data due to radiation effects.