Today in 1972, the Earth Resources Technology Satellite 1 (later renamed Landsat 1) was launched from Vandenberg Air Force Base in CA. The also marked the beginning of the Landsat program, which is still in effect today. The focus of Landsat is to gather information about Earth, such as its agriculture, geology, oceanography, and meteorology. The most recent launch, Landsat 8, took place in February 2013. Landsat 9 is already being developed and is planned to be launched in December 2020.
Image Credit: NASA