Pointing, acquisition, and tracking system for the free-space laser communication system SILEX

The flight hardware for the European Semiconductor laser Intersatellite Link EXperiment, SILEX, is presently under integration. Qualification at equipment level has been performed during 1994 and performance testing at subsystem level is being undertaken. This paper describes the design requirements, the actual design, and the tests of the Pointing Acquisition and Tracking subsystem. It can be summarized in the following headlines: Mission overview, system tracking and pointing strategy, terminal design, PAT subsystem requirements, PAT equipment design, PAT subsystem design, and on ground verification approach.