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.
Westar 1
Westar 1 was America's first domestic and commercially launched geostationary communications satellite, launched by Western Union (WU) and NASA on April 13, 1974. It was built by Hughes for Western Union, using the HS-333 platform of spin-stabilized satellites. Westar 1 was the first of five Westar satellites launched by Western Union from 1974 to 1982. Westars 1, 2, and 3 were 12-transponder satellites while Westar 4 and Westar 5 were launched with 24 transponders. Western Union built a teleport in Cedar Hill, Texas, to uplink content to the Westar satellites (it was interconnected to WU's existing terrestrial microwave network at the time), and another teleport that, in addition to uplink services, would become the main TT&C (telemetry, tracking & control) center for the satellite (and for all of the Westar fleet later on), in Glenwood, New Jersey. A sixth satellite, Westar 6, was launched in 1984 but failed to reach orbit and was retrieved by the STS-51-A Space Shuttle mission later that year. It was later refurbished and relaunched in orbit of Asia as AsiaSat 1 in 1990.