The United States of America, under the leadership of Richard Nixon, launched Landsat-1, the first satellite of what began the US’ Landsat program – the longest running program for the acquisition of satellite imagery of Earth. (We are now up to Landsat 8, launched four years ago on February 11, 2013.)
As succinctly summarized by Wikipedia, the images collected and archived at receiving stations around the world are a unique resource for global change research and applications in agriculture, cartography, geology, forestry, regional planning, surveillance and education, and can be viewed through the U.S. Geological Survey (USGS) ‘EarthExplorer‘ website. For example, the latest, Landsat 7, records data across eight spectral bands with resolutions ranging from 15 to 60 meters and a temporal resolution of 16 days.
And while Landsat 1 only had two sensors, the return beam vidicon (RBV) and a first generation multispectral scanner (MSS) that recorded, respectively, visible and near infrared photographic images and radiometric images, this was still extremely valuable imaging data where none had existed before. And without it, we’d never have Google Earth.