Fiber-Optical Sensing On-Board Spacecraft

Paper number

IAC-15,D1,2,3,x31066

Author

Mr. Norbert M.K. Lemke, OHB System AG - Munich, Germany

Coauthor

Mr. Andreas Hurni, OHB System AG - Munich, Germany

Coauthor

Mr. Philipp Putzer, OHB System AG - Munich, Germany

Coauthor

Mr. Nader Kuhenuri, OHB System AG - Munich, Germany

Year

2015

Abstract

In order to reduce mass, AIT effort and overall costs of classical point-to-point wired temperature ‎sensor harness on-board spacecraft, OHB System has introduced the Hybrid Sensor Bus (HSB) ‎system, which interrogates sensors connected in a bus architecture. In order to use the advantages of ‎electric as well as of fiber optic sensing technologies, the HSB system is a modular measurement ‎system ‎built as combination of an electrical sensor bus based on I²C and a fiber-optic sensor ‎system ‎based on fiber Bragg grating (FBG) sensors.‎

Fiber-optical sensor bus networks on-board satellites are well suited for temperature measurement ‎due to low mass, electro-magnetic insensitivity and the capability to embed them inside structure ‎parts. The light weight FBG sensors inscribed in radiation tolerating fibers can reach every part of ‎the satellite.‎

For the HSB development telecommunication satellite platform requirements have been considered ‎for operating at least 15 years in a geostationary orbit. HSB has been developed in the frame of an ‎ESA program with European and German co-funding and will be verified as flight demonstrator on-‎board the German Heinrich Hertz satellite (H2-Sat).‎

In its basic configuration HSB consists of three modules which are the Intelligent Power Module, ‎the Interrogator Controller Module and the Analog Front-End for the fiber-optical interrogation. The ‎Interrogator Controller Module handles both, the electrical and fiber-optical sensor network. For the ‎latter it is to be completed by the Analog Front End. On this front-end a tunable laser is ‎implemented for the scanning of the FBG sensors.‎

The reflected spectra are measured on multiple fiber channels and are then converted to ‎temperatures by use of a peak find algorithm. To guarantee a stable operation over the full mission ‎an in-orbit recalibration means is implemented on the Analog Front End.‎

In this paper the development of HSB and the analysis of different fiber-optical sensor bus networks ‎are presented. Different approaches for increasing the reliability in fiber-optical sensor bus networks ‎have been modeled and analyzed. Environmental test results of the HSB engineering model with ‎connected space representative fiber-optical sensor networks are presented. The paper concludes with ‎an outlook regarding the HSB flight module development and its in-orbit verification.‎

Abstract document

IAC-15,D1,2,3,x31066.brief.pdf

Manuscript document

IAC-15,D1,2,3,x31066.pdf (🔒 authorized access only).

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