SIMBIOSYS for BepiColombo: the design and qualification of the Italian 'eyes' towards Mercury

摘要

The SIMBIOSYS (Spectrometer and Imaging for MPO BepiColombo Integrated Observatory SYStem) is aninstrument suite part of the scientific payload of the Mercury Planetary Orbiter for the BepiColombo mission, one ofthe cornerstone missions of the European Space Agency (ESA) science mantatory program, devoted to the study ofthe planet Mercury and its environment. SIMBIOSYS consist of a High Resolution Imaging Channel (HRIC), aSTereo imaging Channel (STC) and a VIsual and Infrared Hyperspectral Imager (VIHI) channel, with dedicatedProximity Electronics (PE) and a common main electronics (ME) and power supply (PDU). The scientific objectivesof the instruments are: the study of the surface geology of Mercury, of its magmatic activity, global tectonics, age ofthe main geological provinces and the surface composition. Selex Galileo (SG) is in charge of the instrumentrealization under a contract of the Italian Space Agency (ASI), with CNES contributions by IAS and LESIAinstitutes, i.e. the development of VIHI PE, ME and system final calibration. In this paper, the design and earlyqualification of SIMBIOSYS instrument is described, with particular emphasis to the challenging innovative aspectsencountered during the development phases. The complex architecture incorporates the three independent channels(STC, VIHI, HRIC) with dedicated baffles, detectors and a proximity electronics, while the power resources and thecontrol are shared, so that operation modes and functional timeline must be optimized. Each optical design has beentailored with respect to the mission objectives. The detectors, CMOS matrix type, needed a complex requirementsdefinition phase and a dedicated procurement activity. The design has been mainly driven by the limited on boardresources and strict environmental conditions imposed by the particular mission characteristics, the most critical,experienced during the transfer phase, were the high mechanical loads caused by the modules separations, whileduring the operative phase in Mercury orbit, were the irradiative and thermal harsh conditions due to the proximity ofthe Sun. Also the contamination aspects have been carefully considered in the SIMBIOSYS channels development.The development philosophy was harmonized accordingly to the one of the spacecraft, managed by Astrium underESA responsibility, in order to satisfy the mission technical and scientific requirements.