The Landsat program is a joint USGS and NASA led enterprise for Earth Observation that represents the world's longest running system of satellites for moderate-resolution optical remote sensing for land, coastal areas and shallow waters.
Since 1972, Landsat satellites have provided EO data to support work in agriculture, geology, forestry, education, mapping, emergency response and disaster relief, as well as providing a long-term record of natural and human-induced changes to the Earth.
Landsat's Global Survey Mission is to establish and execute a data acquisition strategy that ensures repetitive acquisition of observations over the Earth's land mass, coastal boundaries, and coral reefs and consists of a series of eight satellites, the first seven of which are presented herein. As technological capabilities improved, instruments on board consecutive missions changed. Subsequently, three ‘families' of Landsat satellites have been distinguished based on sensor and platform characteristics:
Landsat 1, Landsat 2 & Landsat 3:with the Multi Spectral Scanner (MSS) and Return-Beam Vidicon (RBV) instruments as the payload on a ‘Nimbus like' platform.
Landsat 4 & Landsat 5: with the MSS and Thematic Mapper (TM) instruments on the Multi-mission Modular Spacecraft (MMS) platform.
The European Space Agency (ESA) is part of the Landsat International Ground Station (IGS) Network and in effect operates the ground stations within Europe as well as repatriating Landsat data from stations in the US, Brazil and Canada. In parallel with the USGS activities, ESA have developed and operate their own processing system / archiving system / receiving station for Landsat which allows users to access an important collection of historical products.