Optoelectronic link for optical satellite harnessing substitution in space communications

The current space harness has limitations associated with the use of copper cables in the intra-satellite networks: mass, volume and limited data rate for a given link distance. To overcome these limitations the space community has identified fibre optics as a desired solution for payload and potentially for platform applications. EADS CASA Espacio and DAS Photonics have already been working developing an opto electronic conversion module to use fibre optic in control buses (MIL-STD-1553 and CAN BUS) and point-to-point links (SpaceWire, clocks, AOCS, TM/TC…) to serve as a drop–in replacement for present copper solutions. The mechanical design was done to fit conventional connectors plus backshell dimensions with similar mass. The use of optical fibre instead of copper allows for mass reduction of 25% in typical satellite. All of Engineering Model's (EM) employ 850 nm vertical cavity surface lasers, GaAs PIN photodiodes, radhard graded index multimode fibre (50/125 μm), space qualified optical and electrical connectors with all materials and processes suitable for space applications All modules survived the test campaign without performance degradation or failures. Based on test results, the transceivers are promising candidates to substitute copper harness in the short term, for communication protocols used in satellites at low and medium data rates.