The European Space Agency (ESA) is preparing for the launch of the Sentinel 3b Earth-observing satellite; it is due for launch on April 25, 2018 from the Plesetsk launch site in Russia. The Sentinel 3 mission is based on two identical satellites orbiting in constellation to cover the globe; carrying a suite of instruments, Sentinel 3 measures the Earth’s oceans, land, ice, and atmosphere to monitor large-scale global dynamics. The mission is the result of the collaboration between ESA, the European Commission, Eumetsat, France’s CNES space agency, industry service providers, and data users.
The original Sentinel satellite, 3A, was launched on February 16, 2016. When 3B joins 3A in space after its April launch, coverage of the entire globe can be possible every two days.The Sentinel 3 satellites measures the temperature, color, and height of the sea surface as well as the thickness of sea ice. Over land, it monitors wildfires, maps the way land is used, provides indices of vegetation state, and measures the height of rivers and lakes. These measurements will be used to monitor any changes in sea level, marine pollution, and biological productivity of both land and sea.
ESA and Eumetsat will manage the Sentinel 3 mission together. ESA will process land products while Eumetsat will process marine products for application through the Copernicus services. Copernicus is the new name for the Global Monitoring for Environment and Security program, previously known as GMES. Headed by the European Commission in partnership with the European Space Agency, Copernicus provides free data to users worldwide.
Other Sentinel satellites are part of the Copernicus program. Sentinel 1A and 1B launched in April of 2014 and April 2016 respectively, providing day and night weather RADAR imagery. Sentinel 2A, which launched in June of 2015, provides high-resolution optical images of land; it was joined by it’s twin, the 2B in March of 2017. The Sentinel 3A was launched in February of 2016 and provides ocean and land data for Copernicus. The Sentinel 5P was launched in October 2017 and monitors the atmosphere. Eventually, Sentinel 4 and 5 will be launched, providing atmospheric composition monitoring from geostationary and polar orbits. According to ESA, Copernicus “provides a unified system through which vast amounts of data are fed into a range of thematic information services designed to benefit the environment, the way we live, humanitarian needs and support effective policy-making for a more sustainable future.”