February 7, 2017

Ground Segment

During its lifetime the Euclid mission will deliver an unprecedented volume of data for a space mission: about 850 Gbits of compressed data per day. Lossless compression will be applied, with compression rates of the order 2 to 3. This data stream will be handled by the Euclid ground segment.

The concept for the Euclid ground segment maximizes sharing and re-use of manpower, facilities and tools from the Science Observatory family of missions. The spacecraft will be autonomous during most of the commissioning and routine operational phases.

Operations ground segment

All control, telecommand and housekeeping telemetry communications with Euclid will be performed via X-band (8.0-8.4 GHz). K-band (25.5-27 GHz) will be used for the science data downlink. The ground station network for Euclid during the Launch and Early Operations Phase (LEOP) will be composed of the 15-metre antenna at Kourou and the 35-metre antennas at New Norcia and Cebreros (or the Cebreros antenna in combination with the 15-metre antenna at Mas Palomas). This network gives almost 24-hour coverage of the spacecraft during this critical period.

For all following phases, the Cebreros ground station, with its 35-m antenna upgraded for K-band downlink, will be used for all communications with Euclid. The daily communication period will be 4 hours.

The Mission Operations Centre (MOC), in charge of flight operations, will be at ESA's European Space Operations Centre (ESOC) in Darmstadt, Germany, and will be based on an extension of the existing ground segment infrastructure, customized to meet the specific requirements of this mission. The MOC will operate the spacecraft and deliver the raw scientific data to the Science Ground Segment (SGS).

Science ground segment

The Euclid science ground segment consists of the Science Operations Centre (SOC), at ESA's European Space Astronomy Centre (ESAC) in Villafranca (Spain), two Instrument Operations Centres (one for VIS and one for NISP) plus a number of Science Data Centres (SDC) throughout Europe (Science Ground Segment: SGS).

The SOC is responsible for planning observations and monitoring performance. It will act as interface between the MOC and the Instrument Operations Centres for all aspects concerning the operation and monitoring of the scientific instruments. It will also recieve the satellite data, perform first-level processing and supply processed data to the SGS.

The SGS is in charge of data processing (notably correction of instrumental effects) and delivery of science products (images, spectra, etc.). The products are stored in the Euclid Legacy Archive (ELA) for which the SOC acts as custodian. This archive will be accessible by the broad scientific community.