LCT for the European data relay system: in orbit commissioning of the Alphasat and Sentinel 1A LCTs

The European Data Relay System (EDRS) relies on optical communication links between Low Earth Orbit (LEO) and geostationary (GEO) spacecrafts. Data transmission at 1.8 Gbps between the S/Cs will be applied. EDRS is foreseen to go into operation in 2015. As a precursor to the EDRS GEO Laser Communication Terminals (LCT), an LCT is embarked on the Alphasat GEO S/C. Sentinel 1A is a LEO earth observation satellite as part of ESAs Copernicus program and carries an LCT on board. Both the Alphasat and the Sentinel 1A LCT have completed their individual in orbit commissioning and a joint link commissioning phase, with first LEO to GEO optical communication links in 2014. In this presentation, the design principle of the LCT applied for EDRS will be investigated. The most recent results of the in-orbit link commissioning phase of the LCTs on board of Alphasat and Sentinel 1A will be presented.