The increasing resolution of earth observation sensors will require much higher data rates for the data downlink in future than is feasible with conventional RF-technology. This applies for earth observation satellites as well as for aeronautic observation platforms, such as aircraft or stratospheric high altitude platforms. The most promising solution for this data downlink bottleneck is the application of optical free space transmission technologies. DLR has built diverse atmospheric flight terminals and performed several trials of optical downlinks from space (together with partnering organizations) as well as from atmospheric carriers in recent years. Here we present and compare results of such communication system trials
