Satellite laser communication hardware design that supports space-based optical communications, and successful hardware demonstrations, are presented for Low Earth Orbit (LEO) terminals. For inter-satellite links (ISL), the design of an optical module has been optimized to support satellite-to-satellite relays. Providing optical line-of-sight (LOS) stabilization, the Optical Bench Assembly (OBA) is the modular component that includes the LOS jitter rejection control loop system, which stabilizes the transmit (Tx) and receive (Rx) data channels. The jitter rejection system design of the OBA is described. The demonstrated performance is reported for the nested control loop rejecting the host platform’s on-orbit vibration profile.
The backend optical assembly module for a space-based, laser communication terminal is presented. The backend optical assembly utilizes voice coil-fast steering mirror technology embedded into a control loop that both provides terminal-level pointing capability, and maintains receive channel fiber coupling. The fast steering mirror technology presents a technical solution for operating within the space environment, while simultaneously meeting the bandwidth requirements for characteristic satellite vibration profiles. The system’s architecture design meets the demands of onplatform, jitter-rejection performance to establish and maintain a communication link.
Axisymmetric optical components such as lenses are frequently centered with the use of rotary air bearings, guided
by optical instrumentation that use reflected or transmitted light. This report systematically explores methods of
adjusting optical elements including wedged-shims, fine pitch screws, and positioning rods with a goal of defining the
accuracy that can be expected. Analysis of the performance is supported with experimental data. A characterization and
discussion of the merits of each positioning method is additionally presented.