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.
Wideband Global SATCOM
The first launch (WGS-1) was conducted by United Launch Alliance (ULA) on 1 October 10, 2007. The satellite was carried by an Atlas V (421) lifting off from LC-41 at Cape Canaveral Air Force Station (CCAFS). After launch, the WGS-1 satellite was given the US military designation "USA-195". Its coverage area stretches from the U.S. western coast to Southeast Asia.
Launch of the second satellite (WGS-2) was also conducted by ULA, at 01:31 UTC on April 4, 2009, using an Atlas V 421. A ULA Delta IV flying from LC-37B at CCAFS launched the third spacecraft on 6 December 2009. The WGS-2 satellite was positioned over the equator around 60° East longitude (over the Indian Ocean) for use by U.S. Central Command in Afghanistan, Iraq and other parts of Southwest Asia. Originally, the second spacecraft was to fly on the Delta, and the third on the Atlas, but they were switched for an undisclosed reason.
WGS-3 was launched on December 6, 2009, covers the eastern Atlantic Ocean. The satellite was launched by a Delta IV "Medium+ (5,4)" rocket (originally Atlas V but switched with WGS-2; see above).