A long string of Earth-observing orbiters began with NASA's Earth Resources Technology Satellite (ERTS). Launched in July 1972, it was the first satellite explicitly designed to study our planet. Three years later, the satellite was renamed Landsat 1. Outlasting its one-year design, Landsat 1 retired in January 1978.
Landsat 1 First Light Image over Dallas, Texas
The very first image in the Landsat archive is the MSS image above, showing the Dallas - Fort Worth area of Texas on July 25, 1972. The resolution is 60 meters per pixel in this false-color image, where shades of red indicate vegetated land and grays and whites are urban or rocky surfaces.