In the Spotlight
Sentinel-3B ready for launch

The European Space Agency’s latest Earth observation satellite, Sentinel-3B, will be orbited by a Rockot launcher from the Plesetsk Cosmodrome on April 25. Sentinel-3B has a two-pronged maritime and terrestrial mission, spanning oceanography, land hydrology and vegetation monitoring on land.
Taking a close look at our oceans
Land Ho!
Services based on Sentinel-3B data will greatly benefit agriculture as well. Having accurate and up-to-date information is an ideal way to help farmers monitor any changes in their crops and land use. This data can also be used either globally or even locally, since we are seeing a real boom in small and medium-size businesses that are developing services based on data from Sentinel-3A (Sentinel-3B’s twin, operational in orbit since 2016). One of the examples cited regularly by ESA concerns a consortium of 25 truck farmers in the Netherlands, who are already using data generated by Sentinel-3A to optimize their expansion and monitor the “health” of their production.
In addition to global monitoring of oceans, the Sentinel-3 satellites also measure river height and water quality (to detect any source of pollution or bacteriological contamination). Once again, a number of SMEs have begun developing services and applications in this area, in particular to analyze areas that are difficult to reach any other way.
The four instruments on Sentinel-3B
- Two optical instruments: OLCI (Ocean and Land Color Instrument) and SLSTR (Sea and Land Surface Temperature Radiometer).
- Two RF (radio-frequency) instruments: SRAL (Synthetic-aperture Radar ALtimeter), and MWR (Microwave Radiometer), which will provide measurements to determine the topography of oceans, ice, sea ice and water bodies on land.
Copernicus and the waltz of the Sentinels
The Sentinel spacecraft are developed on behalf of ESA within the scope of the European Union’s Copernicus program. They are a key to Europe’s environmental monitoring efforts. There are actually six Sentinel families, of satellites or instruments: Sentinel-1 is designed to provide continuity for the radar data collected by ERS and Envisat; Sentinel-2 and -3 are dedicated to monitoring land and oceans. The Sentinel-4 and -5 instruments are designed for meteorology and climatology missions. Sentinel-6 will provide operational continuity for Jason altimetry missions. Thales Alenia Space is prime contractor for the Sentinel-1 and -3 families (4 satellites each), is in charge of the image ground segment for Sentinel-2, and makes the imaging spectrometer carried by Sentinel-5P as well as the Poseidon-4 radar altimeter for the Jason-CS/Sentinel-6 mission. Copyrights:
Artistic views 1, 3 &7: © ESA
Photos 2, 4 & 6: © Thales Alenia Space/Master Image Programmes
Photo 5: © Thales Alenia Space/Imag[IN]