A European Space Agency (ESA) environment satellite with 10 instruments aboard. At eight tonnes it is the largest civilian Earth observation mission, one designed to measure the atmosphere, ocean, land, and ice. It was launched on 28 February 2002 into a polar orbit on a five-year mission. The satellite outlasted its life expectancy, contributing data for 10 years. Its data were added to previous measurements by ESA's European Remote-Sensing Satellite (ERS) series and have been used to monitor environmental and climatic changes, such as mapping the gradual decline of Arctic sea ice and tracking the regular opening of polar shipping routes in the summer months. The mission ended on 8 April 2012, following the unexpected loss of contact with the satellite.