Robust and Efficient OBDH Core Module for the Flexible Picosatellite Bus UWE-3

Pursuing the ambitious goal to establish formations of cooperating small satellites, the University of Wuerzburg established a road map for technology implementations leading towards the realization of coordinated formations of picosatellites. Within the recent developments of the third generation of UWE satellites, special focus was put on the design of a robust and efficient Onboard Data Handling core module. The core module plays a central role in the design philosophy of the UWE-3 bus as it can be seen as the fundamental core which is the only subsystem continuously operating. It is built around two redundant ultra low power microcontrollers in dynamically decided master-slave configuration. One of the main features of the core module software is its flash protection and recovery, where both microcontrollers mutually protect each other by periodically comparing the content of the flash memories with each other and perform corrections if required. This contribution gives a short overview of the UWE-3 picosatellite bus and elaborates in detail on design and test of the OBDH core module.