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Future science missions will need higher bandwidth in the Gbit/s range for intra-satellite communications, so the step from electrical transmission media towards fiber-optical media is the logical next step to cope with future requirements. In addition, the fibers can be used to monitor temperatures directly underneath satellite payloads which will reduce the integration effort in a later phase. For temperature monitoring so called fiber Bragg gratings (FBGs) are written in special radiation tolerant fibers, which reflection wavelength allows a direct link to temperature at the grating position. A read-out system for FBGs to use within satellite applications is currently under development at OHB. For this study, first the environmental requirements for the panels are derived and in a second stage the functional requirements are defined. To define the functional requirements a telecommunication satellite platform, in the case here the Small-GEO series from OHB, has been taken as baseline. Based on the configuration of temperature sensors, communication lines and electrical signaling a possible replacement by fiber-optical technology was defined and traded w.r.t. its economic benefit. It has been pointed out that the replacement of temperature sensors will reduce harness mass, but the great benefit is seen here in the reduction of assembly effort. Once the satellite panel is manufactured, the temperature sensors are already implemented at certain positions. Another point for mass savings which has pointed out is the replacement of the high-voltage or high- current high power commands (HPC) by fiber optics. Replacing some of the several hundred of required HPC lines with very light-weight fibers would reduce the HPC harness by some tens of kilograms. A detailed table illustrating the mass savings and also the integration time savings will be presented in the paper. To keep the track on an economic solution also a detailed market research was carried out to find suitable components for fiber-optical connectors, fibers and protections buffers. Specially for the connectors a solution based on military qualified connectors pointed out to be the most interesting solution in terms of price and functionality, especially when using multi-pole connectors. The project closes with the construction of a breadboard demonstrator consisting of three different panels, one large panel (ca. 1 m²) and two smaller panels (ca. 0.3 m²). The large panel and one of the small panels are made out of aluminum facesheets whereas the other small panels is made out of CFRP. |
Fiber Bragg gratings
Sensors
Fiber optics
Satellites
Connectors
Transducers
Optical fibers
