July 23, 1972 (, Yam Tze June 13), the United States launched the first Earth Resources Technology Satellite.

the United States on July 23, 1972 launch of the first Earth Resources Technology Satellite, or ERTS. Two years later renamed Landsat (Landsat).
thereafter, in 1975, in succession and fired a total of four the Landsat 2 to Landsat 5. Contained in this satellite sensor imaging high precision, large area coverage, the superiority of the characteristics of temporal and spectral resolution, Landsat image data widely exploited world.
China's "Plan" most of the natural resources, research and development and utilization of information sources, basically following the Landsat image data and numerical information as material. More reliable picture of science, but also a certain degree of economy in China, Japan and more than a dozen countries have established a ground receiving station to facilitate image (no need to be ordered from the United States) to receive data in a timely manner.
Since the satellite into space, remote sensing yield estimation, remote sensing fisheries, as well as remote sensing prospecting will enter a new era in the late seventies, the remote sensing of the United States to the Soviet Union wheat yield estimation accuracy of 94%, and a sensation throughout the world , which set off a remote sensing heat, which are directly related to the Landsat image data, therefore, the first Earth Resources Technology Satellite remote sensing scholars said the successful launch of a new milestone in aerospace history.