Sentinel-3 is an Earth Observation satellite mission developed by the ESA as part of the Global Monitoring for Environment and Security GMES program. GMES is the European programme to establish a European capacity for Earth Observation designed to provide European policy makers and public authorities with accurate and timely information to better manage the environment, understand and mitigate the effects of climate change and ensure civil security.
On the 14th of April 2008, the European Space Agency and Thales Alenia Space signed a €305 million contract to build the first GMES Sentinel-3. Satellite platform was delivered to France for final components assembly in 2013. Communications systems were completed by Thales Alenia Space España in early 2014.
The Sentinel-3 spacecraft will carry six mission-related instruments: the Ocean and Land Colour Instrument (OLCI), the Sea and Land Surface Temperature Radiometer (SLSTR), the Synthetic Aperture Radar Altimeter (SRAL), the DORIS system, a laser retroreflector (LRR), and a microwave radiometer (MWR). The OLCI and SLSTR are optical instruments which will provide data continuity for the Envisat mission. The SRAL, DORIS, and LRR instruments will provide topographic measurements over water, with the SRAL being the primary topographic instrument. The MWR will collect data on atmospheric water vapor and terrestrial thermal radiation.
Additionally, the spacecraft will each carry a GNSS receiver to enable precise orbit determination.
^C. Donlon, B. Berruti, A Buongiorno, M-H Ferreira, P. Femenias, J. Frerick, P. Goryl, U. Klein, H. Laur, C. Mavrocordatos, J. Nieke, H. Rebhan, B. Seitz, J. Stroede, and R. Sciarra, The Global Monitoring for Environment and Security (GMES) Sentinel-3 Mission, Remote Sensing of the Environment, 120,27-57, http://dx.doi.org/10.1016/j.rse.2011.07.024, 2012.