Development and Commissioning Results of the Hybrid Sensor Bus Engineering Qualification Model

In order to reduce mass, AIT effort and overall costs of classical point-to-point wired temperature sensor harness onboard spacecraft OHB System AG has introduced the Hybrid Sensor Bus (HSB) system which interrogates sensors connected in a bus architecture. To use the advantages of electrical as well as of fiber-optical sensing technologies, HSB is designed as a modular measurement system interrogating digital sensors connected on electrical sensor buses based on I2C and fiberoptical sensor buses based on fiber Bragg grating (FBG) sensors inscribed in optical fibers. Fiber-optical sensor bus networks onboard satellites are well suited for temperature measurement due to low mass, electro-magnetic insensitivity and the capability to embed them inside structure parts. The lightweight FBG sensors inscribed in radiation tolerant fibers can reach every part of the satellite. HSB has been developed in the frame of the ESA ARTES program with European and German cofunding and will be verified as flight demonstrator onboard the German Heinrich Hertz satellite (H2Sat). In this paper the Engineering Qualification Model (EQM) development of HSB and first commissioning results are presented. For the HSB development requirements applicable for telecommunication satellite platforms have been considered. This includes an operation of at least 15 years in a geostationary orbit. In Q3/2016‎ the qualification test campaign is planned to be carried out. The HSB EQM undergoes a full qualification according to ECSS. The paper concludes with an outlook regarding this HSB flight demonstrator development and its in-orbit verification (IOV) on board H2Sat.