Military satellite: Difference between revisions

The first military satellites were photographic reconnaissance missions. Some attempts were made to develop [[Space weapon#Space-to-Earth weapons|satellite based weapons]] but this work was halted in 1967 following the ratification of international treaties banning the deployment of weapons of mass destruction in orbit.

As of 2013, there are 950 satellites of all types in Earth orbit. It is not possible to identify the exact number of these that are military satellites partly due to secrecy and partly due to dual purpose missions such as [[GPS]] satellites that serve both civilian and military purposes. As of December 2018 there are 320 known military or dual-use satellites in the sky, half of which are owned by the US, followed by Russia, China and India (13).<ref name=howmany>[https://timesofindia.indiatimes.com/india/why-isros-gsat-7a-launch-is-important-for-iaf/articleshow/67153347.cms Why Isro's Gsat-7A launch is important for the Indian Air Force], Times of India, 19 Dec 2018.</ref>

The first military use of satellites was for redemptionreconnaissance.

In the United States the first formal military satellite programs, Weapon System 117L, was developed in the mid -1950s.<ref name=milsatmag>{{cite web|url=http://www.milsatmagazine.com/story.php?number=1811044549|title=Military Satellite Systems: A History — Part One|date=May 2008|accessdate=2014-01-21|publisher=MilsatMagazine}}</ref> Within this program a number of sub-programs were developed including [[Corona (satellite)|Corona]].<ref name=milsatmag/> Satellites within the Corona program carried different code names. The first launches were code named Discoverer. This mission was a series of [[reconnaissance satellite]]s, designed to enter orbit, take high-resolution photographs and then return the payload to Earth via parachute.<ref name=milsatmag/> [[Discoverer 1]], the first mission, was launched on 28 February 1959 although it didn't carry a payload being intended as a test flight to prove the technology.<ref>{{cite web|publisher=[[NASA]]|title=This Week in NASA History: Discoverer 1|url=https://appel.nasa.gov/2010/02/27/ao_2-2_sf_history-html/|date=23 February 2007|access-date=November 2, 2022}}</ref>} Corona was followed by other programs including [[Canyon (satellite)|Canyon]] (seven launches between 1968 and 1977<ref>{{cite web |url=http://www.planet4589.org/space/jsr/back/news.369 |format=TXT |title=Jonathan's Space Report : No. 369 |website=Planet4589.org |accessdate=2016-02-27 |archive-url=https://web.archive.org/web/20090619224722/http://www.planet4589.org/space/jsr/back/news.369 |archive-date=2009-06-19 |url-status=dead }}</ref>), [[Aquacade (satellite)|Aquacade]]<ref>{{cite book|author=James Bamford|title=The Shadow Factory|year=2008|publisher=Doubleday|page=[https://archive.org/details/shadowfactory00bamf/page/176 176]|author-link=James Bamford|title-link=The Shadow Factory}}</ref> and [[Orion (satellite)|Orion]] (stated by US Government sources to be extremely large<ref name="afa100913">{{cite web | title=National Reconnaissance Office Update | url=http://www.afa.org/events/conference/2010/scripts/AFA-100913-Carlson.pdf | author=Bruce Carlson | publisher=Air & Space Conference and Technology Exposition 2010 | accessdate=2010-11-25 | date=2010-09-13 | archive-url=https://web.archive.org/web/20101206140015/http://www.afa.org/events/conference/2010/scripts/AFA-100913-Carlson.pdf | archive-date=2010-12-06 | url-status=dead }}</ref>). There have also been a number of subsequent programs including [[Magnum (satellite)|Magnum]] and [[Trumpet (satellite)|Trumpet]],<ref>{{cite web|url=http://www.zeit.de/1995/31/Riesige_Lauscher_am_Himmel|title=Riesige Lauscher am Himmel|publisher=Die Zeit|date=28 July 1995}}</ref> but these remain classified and therefore many details remain speculative.

The [[Soviet Union]] began the [[Almaz]] ({{lang-langx|ru|Алмаз}}) program in the early 1960s. This program involved placing space stations in Earth orbit as an alternative to satellites. Three stations were launched between 1973 and 1976: [[Salyut 2]], [[Salyut 3]] and [[Salyut 5]]. Following Salyut 5, the Soviet Ministry of Defence judged in 1978 that the time consumed by station maintenance outweighed the benefits relative to automatic reconnaissance satellites.{{citation needed|date=January 2014}}

In 2015, United States military space units, and commercial satellite operator [[Intelsat]], became concerned about apparent reconnaissance test maneuvers by the [[Government of Russia|Russian]] [[Luch (satellite)|Luch]] (or [[Olymp-K|Olymp]]) satellite which was, launched in September 2014, when it maneuvered between the [[Intelsat 7]] and [[Intelsat 901]] satellites, which are located only half a degree from one another in [[geosynchronous orbit]].<ref name="sn20151009">

The first [[satellite navigation]] system, [[Transit (satellite)|Transit]], used by the [[United States Navy]], was tested in 1960.<ref>{{cite web|last=Howell|first=Elizabeth|title=Navstar: GPS Satellite Network|url=http://www.space.com/19794-navstar.html|publisher=SPACE.com|accessdate=February 14, 2013}}</ref> It used a [[satellite constellation|constellation]] of five satellites and could provide a navigational fix approximately once per hour.

During the [[Cold War]] [[arms race]], the nuclear threat was used to justify the cost of providing a more capable system. These developments led eventually to the deployment of the [[Global Positioning System]] (GPS). The US Navy required precise navigation to enable [[submarine]]s to get an accurate fix of their positions before they launched their SLBMs.<ref>{{cite web|url=http://www.trimble.com/gps/whygps.shtml#0|archiveurl=https://web.archive.org/web/20071018151253/http://www.trimble.com/gps/whygps.shtml#0|archivedate=October 18, 2007|title=Why Did the Department of Defense Develop GPS?|publisher=Trimble Navigation Ltd|accessdate=January 13, 2010}}</ref> The USAF had requirements for a more accurate and reliable navigation system, as did the [[United States Army]] for geodetic surveying <ref>{{cite web|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660002550_1966002550.pdf |title=Release No: 65-333 : Project Geodetic Explorer-A |date=1965-10-29 |website=Ntrs.nasa.gov |accessdate=2016-02-27 |url-status=dead |archive-url=https://web.archive.org/web/20130922061006/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660002550_1966002550.pdf |archive-date=2013-09-22}}</ref> for which purpose they had developed the SECOR system. SECOR used ground-based transmitters from known locations that sent signals to satellite transponder in orbit. A fourth ground-based station, at an undetermined position, could then use those signals to fix its location precisely. The last SECOR satellite was launched in 1969.<ref>{{cite encyclopedia|url=http://www.astronautix.com/craft/secor.htm|title=SECOR Chronology|encyclopedia=Mark Wade's Encyclopedia Astronautica|accessdate=January 19, 2010|url-status=dead|archiveurl=https://web.archive.org/web/20100116213013/http://astronautix.com/craft/secor.htm|archivedate=January 16, 2010}}</ref>

A number of nations have developed satellite based [[missile defense|early warning]] systems designed to detect ICBMs during different flight phases. In the United States these satellites are operated by the [[Defense Support Program]] (DSP). The first launch of a DSP satellite was on 6 November 1970 with the 23rd and last launched 10 November 2007. This program has been superseded by the [[Space-Based Infrared System]] ([[SBIRS]]).

[[Latency (engineering)#Satellite transmission|Signal latency]] is a major concern in satellite communications, so geographic and meteorological factors play an important role in choosing teleports. Since some of the major military activities of the U.S. army isare in foreign territories, the U.S. government needs to subcontract satellite services to foreign carriers headquartered in areas with favorable climate.<ref>{{cite web|url=http://www.newsat.com/Case-Studies/proactive-communications.html/ |archive-url=https://archive.today/20120402124047/http://www.newsat.com/Case-Studies/proactive-communications.html/ |url-status=dead |archive-date=April 2, 2012 |accessdate=September 16, 2011 |title=Defence}}</ref>

Military Strategic and Tactical Relay, or [[Milstar]], is a constellation of military satellites managed by the [[United States AirSpace Force]]. Six spacecraft were launched between 1994 and 2003, of which five are operational, with the sixth lost in a launch failure. They are deployed in [[geostationary orbit]] and provide wideband, narrowband and protected military communication systems. [[Wideband]] systems support high-bandwidth transfers. Protected systems offer more sophisticated security protection like antijam features and nuclear survivability, while [[narrowband]] systems are intended for basic communications services that do not require high bandwidth.

* '''N-1''' For details, see [https://books.google.com/books?vid=ISBN8187966440&id=ZBXL1i-n6UAC&pg=PA4&lpg=PA4&ots=-VlV0cdVwC&dq=space+frontiers+modern+defence&sigpg=58-7qcFZ_azxhCCizuXy7meT8kQPA4 Space: The Frontiers of Modern Defence]

[[Category:Military equipment|Satellite, military]]