Objective: To develop an automatically operated passive optical or radar based sky surveillance system. Targeted Improvements: To enable automated operation of an optical ground station when transmitting potentially non eye-safe laser beams. Description: Opticalcommunication promises the possibility to transmit virtually unlimited amounts of data from optical ground stations (OGS) to futuretelecommunication satellites, without the need for licensing. However, for optical communications from space to ground to become economically viable, an OGS will need to operate autonomously without human presence or supervision. Every optical communication link needs to transmit laser beams which in most cases may not be eye-safe, especially at short range from the OGS. Potential casualties maybecome burglars (intruders into the OGS premises), but also airplane/helicopter/ glider/balloon passengers whose airship may cross the optical beam. This activity will therefore investigate and develop passive optical systems (e.g. camera based sensors in the visible and infra-red) potentially together with radar based systems to identify the presence of airplanes/helicopters/balloons (potentially carrying people) in the vicinity of an uplink optical communication beam from Optical Ground Stations. The system shall be able to continuously monitor (24h per day, 365days per year) during daytime and night time conditions, when optical communication activities are performed. In the case of detection of an aircraft the system shall automatically switch of the laser beam. It shall resume optical communication operations once the detected aircraft has sufficiently moved out of the communication beam hazard area. The system is required to demonstrate 100% reliability for aircraft detection up to a distance of 20 km (TBC).