Satellites are widely used not only in the field of safety and security such as weather observations, disaster situational observations, positionings, explorations, etc., but also in various fields, and satellite-based services have been essential in human life. As the application fields of satellites increase, the market needs for satellites with enhanced functionality expand, and the volume of observation data rises. Therefore, the application of COTS components is necessary to achieve higher satellite performance and high-speed data transmission. This application requires an evaluation of their compatibility for the satellite environment. This paper describes the latest technological trends and the evaluation of reliability in application of COTS components to optical communication devices.