CUBESAT-SCALE LASER COMMUNICATIONS

We report on the development of an optical space‐to‐ground communications system scaled for application in 1.5U CubeSats. The AeroCube Optical Communication and Sensor Demonstration (OCSD) has as its primary payload a 10‐W laser for a LEO‐to‐ground communications demonstration. The OCSD laser is hard‐mounted to the spacecraft and beam steering is accomplished through precision pointing of the spacecraft as a whole. This capability is enabled through development of an advanced CubeSat‐scale attitude‐control system capable of pointing the spacecraft to within 0.2 degrees of the target. The OSCD program includes three flight units; a pathfinder that will fly in summer 2015 and two follow‐on units that will fly in December 2015. It is anticipated that the program will demonstrate optical communication rates of at least 50 Mb/s, with the possibility of rates up to 200 Mb/s. Although not high in comparison with laser communication systems designed for larger spacecraft, the rates represent a 1 to 2 order‐of‐magnitude improvement over RF communication rates typical of CubeSats.