OSIRIS Optical Communication Demonstration on CubeSat

With the increasing need for higher data rates on small LEO spacecraft, highly compact laser communication systems are required to overcome the limitations in the downlink channel. The group of Optical Communication Systems (OCS) at the Institute of Communications and Navigation of the German Aerospace Center (DLR) is working on the program OSIRIS (Optical Space Infrared Downlink System). DLR is closely cooperating with Tesat Spacecom for the industrial application of the OSIRIS technology. CubeSat missions have been seen as technology demonstration missions in the past, but made its way to both scientific as well as commercial missions especially in the framework of Earth Observation and Remote Sensing. Increasing capabilities of small scale sensor systems raised the need for higher data rates in the Direct To Earth (DTE) channel also for CubeSat missions. In the cooperation between DLR and Tesat, the first demonstrator has been developed that will be launched in 2018 to demonstrate the performance of the technology. Therefore, OSIRIS heritage from previous missions has been optimized for the application on a CubeSat. Especially size, weight and power have been taken into account, but also the compatibility to different CubeSat bus interfaces, and influences from a mass manufacturing point of view. The optimization leads to a payload weight of 350 grams and a volume of 0,3 CubeSat units. With an electrical powerconsumption of 8 W, the optical communication payload enables downlink data rates of up to 100 Mbps. This paper will give an overview over the OSIRIS payload and the design constraints, the foreseen mission scenario as well as an investigation on the data throughput together with the commercial application CubeL envisaged after the demonstration mission