Envisat

Envisat, short for Environmental Satellite, was an Earth observation satellite developed and operated by the European Space Agency (ESA). It was launched on 1 March 2002 from the Guiana Space Centre in Kourou aboard an Ariane 5 rocket and was designed to monitor environmental changes on Earth.

The satellite orbited in a near-polar, sun-synchronous trajectory at an altitude of about 800 kilometers, providing regular global coverage. Envisat carried a large payload of instruments designed to observe the atmosphere, land, and oceans, supporting climate research, weather monitoring, and environmental assessment.

Key instruments and capabilities included MERIS (Medium Resolution Imaging Spectrometer) for ocean color, AATSR (Advanced Along-Track Scanning Radiometer) and ASAR (Advanced Synthetic Aperture Radar) for imaging, GOMOS (Global Ozone Monitoring Suite), MIPAS (Michelson Interferometer for Passive Atmospheric Sounding), and SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Chartography) for atmospheric composition. The mission also included the RA-2 radar altimeter for sea surface height, DORIS for precise tracking, and a Laser Retroreflector for satellite laser ranging. Together, these tools measured oceanography, land cover, ice, aerosols, and atmospheric gases.

Envisat operated for more than a decade, far exceeding its nominal design life, and ceased operations in 2012. ESA formally ended the mission in April 2012, and the spacecraft remains in orbit as space debris. The data collected by Envisat contributed to long-term environmental monitoring and informed subsequent European Earth observation programs, including the Sentinel series of the Copernicus program.