The European Space Agency, ESA

Envisat "Launched in 2002, Envisat is the largest Earth Observation spacecraft ever built. It carries ten sophisticated optical and radar instruments to provide continuous observation and monitoring of the Earth's land, atmosphere, oceans and ice caps. [...] Its largest single instrument is the Advanced Synthetic Aperture Radar (ASAR)". More information: http://www.esa.int/export/ esaEO/SEMWYN2VQUD_index_0_m.html

Earth Explorers "Part of ESA's Living Planet Programme, Earth Explorer missions are designed for research purposes. They are divided between two categories: 'Core' missions addressing specific areas of great scientific interest, and faster, lower cost 'Opportunity' missions not necessarily ESA-led. The first Opportunity mission is called CryoSat, focused on polar ice and due to launch in early 2005. The initial Core mission, Gravity Field and Steady-State Ocean Circulation Explorer (GOCE), will follow it in 2006." More information: http://www.esa.int/export/esaEO/SEM9JP2VQUD_index_0_m.html