Evaluation and Qualification of commercial Opto-Electronic Component for the MOHA Subsystem in ESA´s SMOS Mission
Abstract: A dedicated evaluation and qualification campaign has been performed on several optical COTS components in order to use them on ESA’s SMOS mission. The evaluation phase consisted of a set of critical tests and analyses and led to the selection of the flight lot component. After selection of the components, one lot of each component has been qualified for the SMOS mission.
The overall approach is presented together with a summary of all activities performed. The whole task has been handled in a joint effort between ESA, EADS CASA Espacio (prime contractor), Contraves Space AG (MOHA subsystem), TECNOLOGICA SA (component qualification experts) and the respective manufacturers, with each party providing their specific know-how. Test results are presented and the issues discovered and lessons learned are addressed. Special emphasis is given to particular tests for which dedicated setups had to be designed due to the lack of standard equipment.
SMOS (Soil Moisture and Ocean Salinity) is a satellite designed to observe two environmentally very important variables: soil moisture (SM) over land, and ocean-surface salinity (OS). OMOS will provide information on vegetation water content, biomass, snow cover and ice structure and contribute to research on the cryosphere. Knowledge of the global distribution of soil moisture and ocean salinity with adequate spatial and temporal sampling is expected to significantly improve weather, climate and extreme event extremeevent forecasting. The SMOS mission consists of an aperture synthesis radiometer with individual antennas connected to the central correlator unit. An optical fibre harness is used to distribute clock signals to the
individual antennas and also to transmit the returning data signals back to the correlator unit. Optical transmission had been chosen mainly to comply with requirements of signal phase stability over temperature. The MOHA (MIRAS Optical Harness) subsystem provides this optical link.