Ground Segment
Contents
Operations Ground Segment (OGS)
Science Ground Segment (SGS)
Mission Operations
The ARRAKIHS mission ground segment is divided into two major components: the Operations Ground Segment (OGS), fully managed by ESA, and the Science Ground Segment (SGS), jointly managed by ESA and the ARRAKIHS Mission Consortium (AMC). The OGS consists of the Mission Operations Centre (MOC) and ESA’s ground station network, while the SGS includes the Science Operations Centre (SOC) and the Instrument Operations and Science Data Centre (IOSDC). Together, these entities are responsible for spacecraft operations, science planning, data processing, calibration, archiving, and community support.
Operations Ground Segment (OGS)
The OGS consists of the Mission Operations Centre (MOC) and ESA’s ground station network.
- The Mission Operations Centre (MOC), located at ESA’s European Space Operations Centre (ESOC) in Darmstadt, Germany, manages all spacecraft and payload operations throughout the mission lifecycle. Communication with the spacecraft is primarily performed through the Kiruna ESTRACK ground station, with support from Kourou and KSAT Troll when necessary. The mission will use S-band communications for telemetry and commanding, and X-band for science data downlink. The MOC is responsible for spacecraft health and safety monitoring, mission planning, orbit and attitude control, software maintenance, command uplink, telemetry reception, anomaly handling, and the provision of science and housekeeping telemetry to the science segment. The operational concept relies heavily on automation, allowing the spacecraft to operate autonomously for at least 14 days and retain data onboard for at least three days without ground contact.
Science Ground Segment (SGS)
The Science Ground Segment (SGS), includes the Science Operations Centre (SOC) and the Instrument Operations and Science Data Centre (IOSDC).
- The Science Operations Centre (SOC) will be established at ESA’s European Space Astronomy Centre (ESAC) near Madrid. Acting as the interface between the scientific community and mission operations, the SOC is responsible for scientific mission planning, scheduling observations, receiving science and housekeeping data from the MOC, operating the initial stages of the data processing pipeline, performing quality control, tracking survey execution, maintaining the ARRAKIHS Science Archive, distributing data products, and supporting users through documentation, workshops, and helpdesk services.
- The Instrument Operations and Science Data Centre (IOSDC), provided by the ARRAKIHS Mission Consortium, is organized as a distributed infrastructure across consortium countries but presents a single interface to the SOC. It develops and operates the scientific processing pipelines, generates and validates higher-level science products, manages calibration procedures, maintains payload software, supports instrument operations, and monitors instrument performance and health throughout the mission.
Mission Operations
Mission operations begin with a 3-day Launch and Early Operations Phase (LEOP), followed by a 3-month In-Orbit Commissioning (IOC) phase and a 1-month Science Performance Verification and Demonstration (SPVD) phase. During routine operations, the spacecraft executes observation schedules autonomously, performs automatic reaction wheel management, and periodically receives weekly mission timelines from the ground. This highly automated architecture minimizes operational overhead while maximizing scientific efficiency.
Scientific mission planning is divided into long-term plans, covering the entire mission timeline and updated every six months, and short-term plans, covering periods of up to two weeks. These plans integrate survey observations, calibration activities, engineering operations, spacecraft constraints, and filler-program observations. Planning activities are coordinated among the SOC, IOSDC, MOC, and ESA science teams through a dedicated Mission Planning Tool.
Instrument operations are relatively simple because calibration observations are largely performed using the same observing modes as nominal science operations. Calibration activities begin during ground testing and continue throughout the mission. Since ARRAKIHS lacks internal calibration sources and a shutter mechanism, calibration relies on dedicated observations and dark measurements collected during commissioning and routine operations. Instrument health is continuously assessed using Quick Look Analysis (QLA) and Health Monitoring Systems (HMS), which evaluate science data quality and instrument performance after each ground-station contact.