Largest Earth-observation satellite

Envisat was a European Space Agency satellite launched on 1 March 2002. It had a mass of 8,100 kg and measured some 26 x 10 x 5 m. It circled the Earth in a polar orbit once every 100 minutes at an altitude which ranged between 785 and 791 km and provided constant monitoring of Earth’s land and ocean surfaces, ice caps and atmosphere with its array of nine scientific instruments. The Envisat mission ended on 8 April 2012, following the unexpected loss of contact with the satellite.