On a warm July day in 1972, NASA launched a new Earth-imaging satellite called the Earth Resources Technology Satellite. The first Landsat was so successful it led to a series of satellites that have created the longest contiguous record of Earth’s surface from a space-eye view – that continues growing to this day, 50 years later.
Click here for original story, Landsat Legacy: NASA-USGS Program Observing Earth from Space Turns 50
Source: NASA Goddard Center