Fraunhofer satellite radiation sensing systems
Fraunhofer INT develops systems for on-board radiation sensing. On-board in this context means inside electronic boxes on printed circuit boards (PCB) in close proximity to radiation sensitive electronic devices. The ability to measure dose and/or particle fluxes on the PCB is particularly of interest as this is where radiation hurts the most. In case of intense solar particle events the sudden increase of the measured particle fluxes could be used as an input for adaptive radiation mitigation techniques to protect important electronic parts and systems. Furthermore it can help to reduce radiation design margins for future missions because you get a better knowledge of the received dose inside your electronic box in a given radiation environment. In addition in the case of in-orbit verification or validation missions it is of major importance to verify the reliability of your design against the actual dose received. Our approach is to add as little devices as possible and make use of already installed hardware e.g. microprocessors to operate them, so the output of those sensor devices should already be digital. We propose to integrate additional memory devices for radiation sensing on the PCB: non-volatile UV-EPROMs to measure dose and/or SRAMs to detect high energy (solar) particles. The radiation-induced change of their digital content is a measure for the radiation exposure after calibration in a known radiation field. Fraunhofer On-board Radiation Sensors are already accepted to fly on the German geostationary Heinrich Hertz communication satellite as part of the Fraunhofer On-Board Processor and is foreseen to be implemented on-board of a NanoSat.