Earth observation satellite
Earth observation satellites or Earth remote sensing satellites are satellites specifically designed for Earth observation from orbit, similar to spy satellites but intended for non-military uses such as environmental monitoring, meteorology, map making etc. 
The first occurrence of satellite remote sensing can be dated to the launch of the first artificial satellite, Sputnik 1, by the Soviet Union on October 4, 1957. Sputnik 1 sent back radio signals, which scientists used to study the ionosphere.
NASA launched the first American satellite, Explorer 1, in January 31, 1958. The information sent back from its radiation detector led to the discovery of the Earth's Van Allen radiation belts.
The TIROS-1 spacecraft, launched on April 1, 1960 as part of NASA's TIROS (Television Infrared Observation Satellite) Program, sent back the first television footage of weather patterns to be taken from space.
, more than 150 Earth observation satellites were in orbit, recording data with both passive and active sensors and acquiring more than 10 terabits of data daily.
Luigi Broglio
With the launch of Sputnik 1 in 1957, there was a desire from many countries to pursue their own satellite research programmes. In Italy, the influential physicist Edoardo Amaldi in particular would press for the creation of an indigenous programme. Amaldi convinced Broglio to support the idea and both would eventually help form the Italian Space Research Commission, a branch of the National Research Council with the aim of gathering support for an Italian space endeavour. With Broglio as president of the commission, they were successful in lobbying the Italian government to support his proposal for a national programme to set up an offshore equatorial launch base with the support of NASA rockets and crew training. The programme would lead to the launch of the first Italian-built satellite, San Marco 1, the first not built by either of the era's superpowers, the Soviet Union or the United States.