Earth observation - A short historical account |
The modern space age started in October 1957 when a small metal sphere with long antennas was launched into space.
This Soviet Sputnik-1, weighing 83 kg, was the world's first artificial satellite.
|Satellites with both optic and radar instruments|
|The world's most advanced environmental satellite, Envisat, was launched the night before 1st March.|
|Satellites with optical sensors|
|Sputnik-1 was a simple satellite. It consisted of a metal sphere half a meter high, which contained a radio transmitter, and also four radio antennas.|
|Instruments on board in radar satellites transmit radar beams towards the surface of the Earth. The first satellite of this type, Seasat, was developed in the USA by NASA.|