THE OPTEL TERMINAL DEVELOPMENT PROGRAMME - ENABLING TECHNOLOGIES FOR FUTURE OPTICAL CROSSLINK APPLICATIONS

Contraves Space AG is currently developing with support from ESA the OPTEL family of optical inter- satellite link (O-ISL) terminals for commercial optical satellite crosslinks. The OPTEL family comprises three terminals designed to meet all interesting O-ISL applications ranging from short range links (typically 2,000 km distance) to long range links (up to 80,000 km). The scope of these projects is to develop the technologies needed for the OPTEL terminal best positioned to meet near term market opportunities for commercial O-ISL, and to also bring these technologies together in order to produce a complete O-ISL terminal that can be demonstrated to future customers. The near term market identified by Contraves Space for this technology is for medium range (typically 25,000 km) crosslinks between geostationary communication satellites that carry conventional transparent Ku-band payloads. The member of the OPTEL family that was selected is the OPTEL-25 GEO terminal. The flight design and performance of the OPTEL-25 GEO terminal is to be verified through a two phase test campaign. In the first phase the optical subsystem, pointing and tracking performance are verified through testing of the optical head unit and associated control electronics. Within the second phase a complete OPTEL-25 GEO terminal comprising optical head unit, electronics unit and laser unit are to be tested together with the embedded software needed to operate the terminal. This paper summarises the results achieved within the laser subsystem development. Secondly, the technologies developed within the Contraves programme and the status achieved will be reviewed. The flight design for the OPTEL-25 GEO terminal will be updated based upon the results obtained in the system level tests to demonstrate the feasibility of the flight design with specific attention paid to verifying the low mass, compact design and performance characteristics of the complete terminal.