Deep-space optical terminals

We report on engineering trades that led to the conceptual design of a laser communications terminal for a spacecraft orbiting Mars. The flight terminal, the ground receiver and the ground transmitter subsystems are described. The designed system is capable of 0.25 Gb/s downlink data-rate, 0.3 Mb/s uplink data-rate, and ranging with a 30 cm precision when the distance to the flight terminal is the Earth-Mars close range (0.42 AU).