Optical inter-satellite communication operational

Optical inter-satellite communication based on TESAT Laser Communication Terminals (LCT's) is operational by now on LEO satellites for more than two years. The LCT's demonstrate their performance in LEO-LEO inter-satellite links (ISL) and they are used also for LEO-to-ground links to investigate beam propagation through the atmosphere. Based on homodyne BPSK, a highly robust and sun light immune modulation scheme, the LCT's offer a full duplex data rate of 5.625 Gbps at a bit error rate lower than 10 ^-9 for ISL. The LCT operations in the dynamic LEO scenario has shown that spatial and frequency acquisition can reliably be achieved within a few seconds. Due to its demonstrated performance, TESAT LCT's were selected for the European Data Relay Satellite (EDRS) Program of the European Space Agency. Their performance features makes them well suited also for commercial GEO data relay applications and government system requiring high data rates for LEO-to-GEO and UAV-to-GEO links.