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.
Russian Academy of Sciences
Among the most important achievements of the Academy of the second half of the 20th century, there is, first of all, the Soviet space program. In 1957 the first satellite was launched, in 1961 Yury Gagarin became the first person in space, and in 1971 the first space station Salyut 1 began its operation. Substantial discoveries were also made in the nuclear branch and in other fields of physics. Furthermore, the Academy participated in opening new universities or new study programs in the already existed universities, whose best absolvents started their career at the research institutes of the Academy.