Envisat had 10 instruments to provide continuous observation and monitoring of Earth’s land, atmosphere, oceans and ice caps. Among those instruments, a radar altimeter (RA2), a radiometer (MWR) and complement of precise orbit determination systems.
After its launch in March 2001, the eight-tonne satellite orbited Earth more than 50 000 times over 10 years – twice its planned lifetime. The mission delivered a wealth of data used to study the workings of the Earth system, including insights into factors contributing to climate change.
Contact with Envisat was suddenly lost on 8 April 2012. But ten years of Envisat’s archived data still continues to be exploited for studying our planet.
See more information on ENVISAT on ESA Earth online.
(source : https://www.esa.int/Applications/Observing_the_Earth/Envisat/Mission_overview)