Wikipedia
Envisat ("Environmental Satellite") was a large Earth-observing satellite which still remains in orbit. Operated by the European Space Agency (ESA), it was the worlds largest civilian Earth observation satellite.
It was launched on 1 March 2002 aboard an Ariane 5 from the Guyana Space Centre in Kourou, French Guiana, into a Sun synchronous polar orbit at an altitude of (± ). It orbits the Earth in about 101 minutes with a repeat cycle of 35 days. After losing contact with the satellite on 8 April 2012, ESA formally announced the end of Envisat's mission on 9 May 2012.
Envisat cost €2.3 billion (including €300 million for 5 years of operations) to develop and launch. The mission is due to be replaced by the Sentinel series of satellites. The first of these, Sentinel 1, has taken over the radar duties of Envisat since its launch in 2014.