Satellites

Sentinel-2 has 2 identical satellites in polar sun-synchronous orbit at an altitude of 786 km. Built by Airbus Defence & Space (formerly Astrium Gmbh) and some 60 partner firms, both spacecraft are carrying a single MultiSpectral Instrument (MSI), which has optical detectors sensing in 13 frequency bands.

Each weighing approximately 1.2 tonnes, the 2 satellites were orbited from the spaceport in Kourou atop a European Vega launcher. The Sentinel-2 satellites have a planned service life of at least 7 years, but have enough fuel to operate for 12 years and be safely de-orbited at the end of their mission.

Built around an Astrobus-L spacecraft bus, the satellites have to be precisely oriented to acquire high-resolution imagery. Data from their star tracker, inertial measurement unit (IMU) and GNSS receiver are merged inside the attitude and orbit control subsystem (AOCS).

On each orbital revolution, the Sentinel-2 satellites have to beam back to their European receiving centres the 1.6 Terabytes of multispectral imagery that MSI is capable of recording. Their X-band transmitter communicates with the Copernicus stations in Matera (Italy), Maspalomas (Spain) and Svalbard (Norway), but the satellites are also equipped for optical laser transmissions via the European Data Relay Service (EDRS).

Key facts and figures

Launch:

                Sentinel-2A: 23 June 2015

                Sentinel-2B: 7 March 2017


Launcher:
                European Vega launcher from Kourou, French Guiana


Orbit:
                Polar sun-synchronous, 786 km, local equator crossing time at descending node of 10:30 a.m.

Revisit rate:
                5 days for all of Earth’s land surfaces.


Mission lifetime:
                7 years (enough fuel for 12 years)


Satellite dimensions:
                3.4 m x 1.8 m x 2.35 m


Instrument:
                MSI (MultiSpectral Instrument)


Receiving stations:

                Science data: EDRS (satellites)/Copernicus ground stations

                Telemetry data: Kiruna, Sweden


Applications:

                Earth mapping

                Land occupancy
                Soil moisture
                Vegetation and forest cover

                Glacier monitoring

                Coastal monitoring
                Agriculture and arable land management

                Lake monitoring

                Natural disaster monitoring


Main contractors:

                Airbus Defence & Space (ex. Astrium Gmbh) for the satellites

                Airbus Defence & Space (ex Astrium SAS) for MSI


Data access:
                Copernicus website: http://sentinels.copernicus.eu