Military satellite

Military satellites are satellites used for military purposes. The task areas such satellites originally include communication, stakeout and orientation. Be entertained such satellites from all the major nations that have the ability to launch such satellites.

By 1959 the U.S. began with the launch of spy satellites (codenamed Corona ), whose images had a resolution of about 7.5 meters and brought their images by exposing film canisters back to Earth. From about 1976, began the digital age here. The resolution at this time was about 15 centimeters. Today's resolutions should be between ten to less than four centimeters.

Military communications satellites are in global armies to transfer commands and information. Current members of this category are, for example, the U.S. Milstar satellites, of which since 1994 six were shot into space.

The positioning and navigation finally is a further area of ​​application of military satellites. To this end, the United States developed the Global Positioning System. This allows for a relatively accurate determination ( 10 m) of military units, but is also used for the control of cruise missiles. The signals from these satellites are now used for civilian navigation, in times of crisis can also be encrypted so that the overall accuracy is poor or the system fails completely. This led to the development initially for purely civilian purposes intended positioning and navigation systems (Galileo).

A future area could be used as weapons or armed satellites. As early as 1983 under Ronald Reagan began in the U.S. with the Strategic Defense Initiative, which was founded in 1993 but discontinued due to major technical problems and high costs. Under the administration of George W. Bush, the program was revived and tackled again promoted; it is now called National Missile Defense ( National Missile Defense ). This one focuses on both ground-based interceptor missiles and other defense systems such as high-energy lasers ( see, eg, Airborne Laser ) and on space weapons.

It should be noted that today many commercial and scientific satellites have also built a military component or be used in dual use. Well-known examples are the GPS satellites and all high resolution earth observation satellites, such as Landsat.