The aim is to investigate the fundamentals of satellite-optical communications. A satellite is an electronic device launched into space to facilitate communication. Conventionally, microwaves are used to transmit and receive signals. The development of optical technologies and its application for satellite communication allows for high data rate and reduced cost. The signals are modulated into optical carrier mainly using Nd:YAG lasers, and detected using pin or avalanche photo-detectors. Currently, the satellite-optical links are point to point, thus Time Division Multiple Access proves to be the suitable method to maximize the transponder use. Notable shortcoming of the optical carrier is its lesser capacity to penetrate atmospheric noise. During times of bad weather the capacity of optical links are significantly reduced or blocked. Also, the requirement for the satellite to be highly stable to establish the optical link is a major challenge. Nevertheless, ever high communication demands place optical - satellite communication technology to be among the vibrant fields in the communication industry.