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.
Science and technology in Malaysia
The first satellite operated by Malaysia was during 1996 when a private company, MEASAT Satellite Systems Sdn. Bhd (formerly known as Binariang Satellite Systems Sdn. Bhd) bought 2 communications satellites from Boeing Satellite Systems named them MEASAT-1 and MEASAT-2. MEASAT-3 and MEASAT-3A was launched on 2006 and 2009 respectively. Malaysia successfully designed and built its first remote sensing satellite named TiungSAT-1 through collaboration between Astronautic Technology Sdn Bhd in Malaysia and Surrey Satellite Technology Ltd. in the United Kingdom. The satellite was launched into low Earth orbit on 26 September 2000 at Baikonur Cosmodrome, Kazakhstan. Malaysia's second remote sensing satellite, RazakSAT was launched on 14 July 2009 and RazakSAT-2 was planned to be launched in 2015.