Shock-Identification-Computer on Board of the Spacecrafts HELIOS-1 and HELIOS-2

One of the most important goals of the HELIOS-1 and -2 missions is the investigation of discontinuities with strong variations in the magnetic-field magnitude as, for example, shock waves. Observational studies of such events with high time resolution at low telemetry rates require an on-board automatic identification system and a big core memory. For this purpose a quality index is calculated on board using both a long and short time average of the magnetic-field data. By this quality index the memory read in is triggered. The principle of operation and the technical layout is discussed.