The FAST Spacecraft Instrument Data Processing Unit

The Fast Auroral Snapshot Explorer (FAST) is the second of the Small Explorer Missions which are designed to provide low cost space flight opportunities to the scientific community. FAST performs high time resolution measurements of the auroral zone in order to resolve the microphysics of the auroral acceleration region. Its primary science objectives necessitate high data volume, real-time command capability, and control of science data collection on suborbital time scales. The large number of instruments requires a sophisticated Instrument Data Processing Unit (IDPU) to organize the data into the 1 Gbit solid state memory. The large data volume produced by the instruments requires a flexible memory capable of both high data rate snapshots (∼12 Mbit s−1) and coarser survey data collection (∼0.5 Mbit s−1) to place the high rate data in context. In order to optimize the science, onboard triggering algorithms select the snapshots based upon data quality. This paper presents a detailed discussion of the hardware and software design of the FAST IDPU, describing the innovative design that has been essential to the FAST mission's success.