Satellite
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Discospinster
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Reverted edits by [[Special:Contributions/Rush of Rain|Rush of Rain]] to last version by SEWilco (using [[WP:HG|Huggle]])
{{two other uses|artificial satellites|natural satellites, also known as moons|Natural satellite}}
[[Image:ERS 2.jpg|thumb|right|300px|A full size model of the Earth observation satellite [[ERS 2]]]]
In the context of [[spaceflight]], a '''satellite''' is an [[Physical body|object]] which has been placed into [[orbit]] by [[human]] endeavor. Such objects are sometimes called '''artificial satellites''' to distinguish them from [[natural satellite]]s such as the [[Moon]].
== History ==
=== Early conceptions ===
The first fictional depiction of a satellite being launched into orbit is a [[short story]] by [[Edward Everett Hale]], ''[[The Brick Moon]]''. The story was serialized in ''[[The Atlantic Monthly]]'', starting in 1869.<ref>
{{cite web|url=http://www.gutenberg.org/etext/1633|title=The Brick Moon and Other Stories by Edward Everett Hale|publisher=[[Project Gutenberg]]|accessdate=2008-03-06}}</ref><ref>
{{cite web|url=http://cdl.library.cornell.edu/cgi-bin/moa/pageviewer?frames=1&cite=http%3A%2F%2Fcdl.library.cornell.edu%2Fcgi-bin%2Fmoa%2Fmoa-cgi%3Fnotisid%3DABK2934-0024-50&coll=moa&view=50&root=%2Fmoa%2Fatla%2Fatla0024%2F&tif=00005.TIF |title=Contents - The Atlantic monthly. Volume 24, Issue 141|publisher=cornell.edu|accessdate=2008-03-06}}</ref> The idea surfaces again in [[Jules Verne]]'s [[The Begum's Millions]] (1879).
In 1903 [[Konstantin Tsiolkovsky]] (1857–1935) published Исследование мировых пространств реактивными приборами (''The Exploration of Cosmic Space by Means of Reaction Devices''), which is the first academic treatise on the use of rocketry to launch [[spacecraft]]. He calculated the [[orbital speed]] required for a minimal [[orbit]] around the Earth at 8 km/s, and that a [[multi-stage rocket]] fueled by liquid [[propellant]]s could be used to achieve this. He proposed the use of [[liquid hydrogen]] and [[liquid oxygen]], though other combinations can be used.
In 1928 [[Herman Potočnik]] (1892–1929) published his sole book, ''Das Problem der Befahrung des Weltraums - der Raketen-Motor'' (''The Problem of Space Travel — The Rocket Motor''), a plan for a breakthrough into space and a permanent human presence there. He conceived of a space station in detail and calculated its [[geostationary orbit]]. He described the use of orbiting spacecraft for detailed peaceful and military observation of the ground and described how the special conditions of space could be useful for scientific experiments. The book described geostationary satellites (first put forward by Tsiolkovsky) and discussed communication between them and the ground using radio, but fell short of the idea of using satellites for mass broadcasting and as telecommunications relays.
In a 1945 ''[[Wireless World]]'' article the English science fiction writer [[Arthur C. Clarke]] (1917-2008) described in detail the possible use of [[communications satellite]]s for mass communications.<ref>{{citeweb|title=The_1945_Proposal_by_Arthur_C._Clarke_for_Geostationary_Satellite_Communications|url=http://lakdiva.org/clarke/1945ww/|publisher=lakdiva.org|accessdate=2008-03-06}}</ref> Clarke examined the logistics of satellite launch, possible [[orbits]] and other aspects of the creation of a network of world-circling satellites, pointing to the benefits of high-speed global communications. He also suggested that three [[geostationary]] satellites would provide coverage over the entire planet.
=== History of artificial satellites ===
{{Main|Timeline of artificial satellites and space probes}}
{{see also | Space Race}}
The first artificial satellite was [[Sputnik 1]], launched by the [[Soviet Union]] on [[4 October]] [[1957]], and that started the whole [[Soviet]] [[Sputnik program]], with [[Sergei Korolev]] as chief designer. This triggered the [[Space Race]] between the [[Soviet Union]] and the [[United States]].
Sputnik 1 helped to identify the density of high [[Earth's atmosphere#Temperature and the atmospheric layers|atmospheric layers]] through measurement of its orbital change and provided data on [[radio]]-signal distribution in the [[ionosphere]]. Because the satellite's body was filled with pressurized [[nitrogen]], ''Sputnik 1'' also provided the first opportunity for [[meteoroid]] detection, as a loss of internal pressure due to meteoroid penetration of the outer surface would have been evident in the temperature data sent back to Earth. The unanticipated announcement of ''Sputnik 1'''s success precipitated the [[Sputnik crisis]] in the [[United States]] and ignited the so-called [[Space Race]] within the [[Cold War]].
''[[Sputnik 2]]'' was launched on [[November 3]], [[1957]] and carried the first living passenger into orbit, a [[dog]] named [[Laika]].<ref>{{cite web|title=A Brief History of Animals in Space |publisher=''[[NASA]]'' |url=http://history.nasa.gov/animals.html|accessdate=2007-08-08}}</ref>
In May, 1946, [[Project RAND]] had released the [[Preliminary Design of an Experimental World-Circling Spaceship]], which stated, "A satellite vehicle with appropriate instrumentation can be expected to be one of the most potent scientific tools of the Twentieth Century.<ref>
{{citeweb|url=http://www.rand.org/pubs/special_memoranda/SM11827/index.html|title=Preliminary Design of an Experimental World-Circling Spaceship|publisher=[[RAND]]|accessdate=2008-03-06}}</ref>
The [[United States]] had been considering launching [[orbit]]al satellites since 1945 under the [[Bureau of Aeronautics]] of the [[United States Navy]]. The [[United States Air Force]]'s Project RAND eventually released the above report, but did not believe that the satellite was a potential military weapon; rather, they considered it to be a tool for science, politics, and propaganda. In 1954, the Secretary of Defense stated, "I know of no American satellite program."{{Fact|date=May 2008}}
On [[July 29]], [[1955]], the [[White House]] announced that the U.S. intended to launch satellites by the spring of 1958. This became known as [[Project Vanguard]]. On [[July 31]], the Soviets announced that they intended to launch a satellite by the fall of 1957.
Following pressure by the [[American Rocket Society]], the [[National Science Foundation]], and the [[International Geophysical Year]], military interest picked up and in early 1955 the Air Force and Navy were working on [[Project Orbiter]], which involved using a [[Jupiter-C IRBM|Jupiter C rocket]] to launch a satellite. The project succeeded, and [[Explorer 1]] became the United States' first satellite on [[January 31]], [[1958]].<ref>{{citeweb|title=News Reel - First US Satellite Launched|url= http://www.webcastr.com/videos/news/news-reel-first-us-satellite-launched.html|publisher=webcastr.com|accessdate=2008-03-05}}</ref>
The largest artificial satellite currently orbiting the Earth is the [[International Space Station]].
== Space Surveillance Network ==
The [[United States Space Surveillance Network]] (SSN) has been tracking space objects since 1957 when the Soviets opened the space age with the launch of Sputnik I. Since then, the SSN has tracked more than 26,000 space objects orbiting Earth. The SSN currently tracks more than 8,000 man-made orbiting objects. The rest have re-entered Earth's turbulent atmosphere and disintegrated, or survived re-entry and impacted the Earth. The space objects now orbiting Earth range from satellites weighing several tons to pieces of spent rocket bodies weighing only 10 pounds. About seven percent of the space objects are operational satellites (i.e. ~560 satellites), the rest are [[space debris]].<ref>{{citeweb|title=ORBITAL_DEBRIS_EDUCATION_PACKAGE|url=http://www.orbitaldebris.jsc.nasa.gov/library/EducationPackage.pdf|publisher=nasa.gov|accessdate=2008-03-06}}</ref> [[USSTRATCOM]] is primarily interested in the active satellites, but also tracks space debris which upon reentry might otherwise be mistaken for incoming missiles. The SSN tracks space objects that are 10 centimeters in diameter (baseball size) or larger.
== Non-Military Satellite Services ==
There are three basic categories of non-military satellite services:<ref name=Grant&Meadows>Grant, A.,& Meadows, J. (2004). Satellites Communication. Communication Technology Update (ninth edition). Burlington: Focal Press.</ref>
=== Fixed Satellite Service ===
Fixed satellite services handle hundreds of billions of voice, data, and video transmission tasks across all countries and continents between certain points on the earth’s surface
=== Mobile Satellite Systems ===
Mobile satellite systems help connect remote regions, vehicles, ships and aircraft to other parts of the world and/or other mobile or stationary communications units, in addition to serving as navigation systems
=== Scientific Research Satellite (commercial and noncommercial) ===
Scientific research satellites provide us with meteorological information, land survey data (e.g., remote sensing), and other different scientific research applications such as earth science, marine science, and atmospheric research.
==Types==
[[Image:Milstar.jpg|thumb|[[MILSTAR]]: A communication satellite]]
*'''[[Anti-Satellite weapons/"Killer Satellites"]]''' are satellites that are armed, designed to take out enemy warheads, satellites, other space assets. They may have particle weapons, energy weapons, kinetic weapons, nuclear and/or conventional missiles and/or a combination of these weapons. In fiction, one has been featured in the movie ''[[Maximum Overdrive]]'' in which one of these, disguised as a "Weather Satellite" had taken out a [[UFO]] with Class IV nuclear weapons and [[laser|laser cannon]].
*'''[[Astronomical satellite]]s''' are satellites used for observation of distant planets, galaxies, and other outer space objects.
*'''[[Biosatellite]]s''' are satellites designed to carry living organisms, generally for scientific experimentation.
*'''[[Communications satellite]]s''' are satellites stationed in space for the purpose of [[telecommunications]]. Modern communications satellites typically use [[geosynchronous orbit]]s, [[Molniya orbit]]s or [[Low Earth orbit]]s.
*'''[[Miniaturized satellites]]''' are satellites of unusually low weights and small sizes.<ref>{{citeweb|title=Workshop on the Use of Microsatellite Technologies|url=http://www.unoosa.org/pdf/reports/ac105/AC105_903E.pdf|publisher=[[United Nations]]|accessdate=2008-03-06}}</ref> New classifications are used to categorize these satellites: minisatellite (500–200 kg), microsatellite (below 200 kg), nanosatellite (below 10 kg).
*'''[[Global Navigation Satellite System|Navigational satellites]]''' are satellites which use [[radio]] time signals transmitted to enable mobile receivers on the ground to determine their exact location. The relatively clear line of sight between the satellites and receivers on the ground, combined with ever-improving electronics, allows satellite navigation systems to measure location to accuracies on the order of a few meters in real time.
*'''[[Reconnaissance satellite]]s''' are [[Earth observation satellite]] or [[communications satellite]] deployed for [[military]] or [[espionage|intelligence]] applications. Little is known about the full power of these satellites, as governments who operate them usually keep information pertaining to their reconnaissance satellites classified.
*'''[[Earth observation satellite]]s''' are satellites intended for non-military uses such as [[environment (biophysical)|environment]]al monitoring, [[meteorology]], [[map making]] etc. (See especially [[Earth Observing System]].)
*'''[[Space station]]s''' are man-made structures that are designed for [[human|human beings]] to live on in [[outer space]]. A space station is distinguished from other manned [[spacecraft]] by its lack of major [[Spacecraft propulsion|propulsion]] or [[landing]] facilities — instead, other vehicles are used as transport to and from the station. Space stations are designed for medium-term living in [[orbit]], for periods of [[week]]s, [[month]]s, or even [[year]]s.
*'''[[Tether satellite]]s''' are satellites which are connected to another satellite by a thin cable called a [[tether]].
*'''[[Weather satellite]]s''' are primarily used to monitor [[Earth]]'s [[weather]] and [[climate]].<ref>{{citeweb|title=Earth_Observations_from_Space_The_First_50_Years_of_Scientific_Achievements|url=http://dels.nas.edu/dels/rpt_briefs/earth_observations_final.pdf|publisher=nas.edu|accessdate=2008-03-06}}</ref>
==Orbit types==
{{main|List of orbits}}
[[Image:Orbits around earth scale diagram.svg|thumb|Various earth orbits to scale; cyan represents low earth orbit, yellow represents medium earth orbit, the black dashed line represents geosynchronous orbit, the green dash-dot line the orbit of [[Global Positioning System]] (GPS) satellites, and the red dotted line the orbit of the [[International Space Station]] (ISS).]]
The first satellite, [[Sputnik 1]], was put into orbit around [[Earth]] and was therefore in [[geocentric orbit]]. By far this is the most common type of orbit with approximately 2456 artificial satellites orbiting the [[Earth]]. Geocentric orbits may be further classified by their [[altitude]], [[inclination]] and [[Orbital eccentricity|eccentricity]].
The commonly used altitude classifications are [[Low Earth Orbit]] (LEO), [[Medium Earth Orbit]] (MEO) and [[High Earth Orbit]] (HEO). Low Earth orbit is any orbit below 2000 km, and Medium Earth Orbit is any orbit higher than that but still below the altitude for [[geosynchronous orbit]] at 35786 km. High Earth Orbit is any orbit higher than the altitude for geosynchronous orbit.
===Centric classifications===
* '''[[galactic center|Galactocentric orbit]]''': An orbit about the center of a [[galaxy]]. [[Earth]]'s [[sun]] follows this type of orbit about the [[galactic center]] of the [[Milky Way]].
* '''[[Heliocentric orbit]]''': An [[orbit]] around the [[Sun]]. In our [[Solar System]], all [[planets]], [[comets]], and [[asteroids]] are in such orbits, as are many artificial satellites and pieces of [[space debris]]. [[Moons#Moons of the Solar system|Moon]]s by contrast are not in a [[heliocentric orbit]] but rather orbit their parent planet.
* '''[[Geocentric orbit]]''': An orbit around the planet [[Earth]], such as the [[Moon]] or [[artificial satellite]]s. Currently there are approximately 2465 artificial satellites orbiting the [[Earth]].
* '''[[Areocentric orbit]]''': An orbit around the planet [[Mars]], such as [[Mars moons|moon]]s or [[artificial satellite]]s.
===Altitude classifications===
* '''[[Low Earth Orbit]] (LEO)''': [[Geocentric orbit]]s ranging in altitude from 0–2000 [[km]] (0–1240 [[mile]]s)
* '''[[Medium Earth Orbit]] (MEO)''': [[Geocentric orbit]]s ranging in altitude from 2000 [[km]] (1240 [[mile]]s) to just below [[geosynchronous orbit]] at 35786 [[km]] (22240 [[mile]]s). Also known as an [[intermediate circular orbit]].
* '''[[High Earth Orbit]] (HEO)''': [[Geocentric orbit]]s above the altitude of [[geosynchronous orbit]] 35786 [[km]] (22240 [[mile]]s).
[[Image:Orbitalaltitudes.jpg|thumb|Orbital Altitudes of several significant satellites of earth.]]
===Inclination classifications===
* '''[[Inclined orbit]]''': An orbit whose [[inclination]] in reference to the [[equatorial plane]] is not zero degrees.
** '''[[Polar orbit]]''': An [[orbit]] that passes above or nearly above both poles of the planet on each revolution. Therefore it has an [[inclination]] of (or very close to) 90 [[degree (angle)|degree]]s.
** '''Polar [[sun synchronous orbit]]''': A nearly [[polar orbit]] that passes the [[equator]] at the same local time on every pass. Useful for [[image]] taking satellites because [[shadow]]s will be nearly the same on every pass.
===Eccentricity classifications===
* '''[[Circular orbit]]''': An [[orbit]] that has an [[Orbital eccentricity|eccentricity]] of 0 and whose path traces a [[circle]].
** '''[[Hohmann transfer orbit]]''': An orbital maneuver that moves a [[spacecraft]] from one [[circular orbit]] to another using two engine [[impulse]]s. This maneuver was named after [[Walter Hohmann]].
* '''[[Elliptic orbit]]''': An [[orbit]] with an [[Orbital eccentricity|eccentricity]] greater than 0 and less than 1 whose orbit traces the path of an [[ellipse]].
** '''[[Geosynchronous transfer orbit]]''': An [[elliptic orbit]] where the [[perigee]] is at the [[altitude]] of a [[Low Earth Orbit]] (LEO) and the [[apogee]] at the [[altitude]] of a [[geosynchronous orbit]].
** '''[[Geostationary transfer orbit]]''': An [[elliptic orbit]] where the [[perigee]] is at the [[altitude]] of a [[Low Earth Orbit]] (LEO) and the [[apogee]] at the [[altitude]] of a [[geostationary orbit]].
** '''[[Molniya orbit]]''': A highly [[elliptic orbit]] with [[inclination]] of 63.4° and [[orbital period]] of half of a [[sidereal day]] (roughly 12 hours). Such a satellite spends most of its time over a designated area of the [[planet]].
** '''[[Tundra orbit]]''': A highly [[elliptic orbit]] with [[inclination]] of 63.4° and [[orbital period]] of one [[sidereal day]] (roughly 24 hours). Such a satellite spends most of its time over a designated area of the [[planet]].
* '''[[Hyperbolic orbit]]''': An [[orbit]] with the eccentricity greater than 1. Such an orbit also has a [[velocity]] in excess of the [[escape velocity]] and as such, will escape the gravitational pull of the [[planet]] and continue to travel [[infinitely]].
* '''[[Parabolic orbit]]''': An [[orbit]] with the eccentricity equal to 1. Such an orbit also has a [[velocity]] equal to the [[escape velocity]] and therefore will escape the gravitational pull of the [[planet]] and travel until its [[velocity]] [[Relative motion#Relative motion|relative]] to the [[planet]] is 0. If the speed of such an orbit is increased it will become a [[hyperbolic orbit]].
** '''[[Escape orbit]] (EO)''': A high-speed [[parabolic orbit]] where the object has [[escape velocity]] and is moving away from the [[planet]].
** '''[[Capture orbit]]''': A high-speed [[parabolic orbit]] where the object has [[escape velocity]] and is moving toward the [[planet]].
===Synchronous classifications===
* '''[[Synchronous orbit]]''': An orbit where the satellite has an [[orbital period]] equal to the average [[rotational period]] (earth's is: 23 [[hour]]s, 56 [[minute]]s, 4.091 [[second]]s) of the body being orbited and in the same direction of rotation as that body. To a ground observer such a satellite would trace an [[analemma]] (figure 8) in the sky.
* '''[[Semi-synchronous orbit]] (SSO)''': An [[orbit]] with an [[altitude]] of approximately 20200 km (12544.2 miles) and an [[orbital period]] equal to one-half of the average [[rotational period]] (earth's is approximately 12 hours) of the body being orbited
* '''[[Geosynchronous orbit]] (GEO)''': Orbits with an altitude of approximately 35786 km (22240 miles). Such a satellite would trace an [[analemma]] (figure 8) in the sky.
** '''[[Geostationary orbit]] (GSO)''': A [[geosynchronous orbit]] with an [[inclination]] of zero. To an observer on the ground this satellite would appear as a fixed point in the sky.<ref>{{citeweb|title=PEARL HARBOR IN SPACE|url=http://www.jamesoberg.com/pearl.html|publisher=jamesoberg.com|accessdate=2008-03-06}}</ref>
*** '''[[Clarke orbit]]''': Another name for a [[geostationary orbit]]. Named after scientist and writer [[Arthur C. Clarke]].
** '''[[Supersynchronous orbit]]''': A disposal / storage orbit above GSO/GEO. Satellites will drift west. Also a [[synonym]] for Disposal orbit.
** '''[[Subsynchronous orbit]]''': A drift orbit close to but below GSO/GEO. Satellites will drift east.
** '''[[Graveyard orbit]]''': An orbit a few hundred kilometers above [[geosynchronous]] that satellites are moved into at the end of their operation.
*** '''[[Disposal orbit]]''': A [[synonym]] for [[graveyard orbit]].
*** '''[[Junk orbit]]''': A [[synonym]] for [[graveyard orbit]].
* '''[[Areosynchronous orbit]]''': A [[synchronous orbit]] around the planet [[Mars]] with an [[orbital period]] equal in length to Mars' [[sidereal day]], 24,6229 [[hours]].
* '''[[Areostationary orbit]] (ASO)''': A [[circular]] [[areosynchronous orbit]] on the [[equatorial plane]] and about 17000 [[km]](10557 [[mile]]s) above the surface. To an observer on the ground this satellite would appear as a fixed point in the sky.
* '''[[Heliosynchronous orbit]]''': An [[heliocentric orbit]] about the [[Sun]] where the satellite's [[orbital period]] matches the [[Sun]]'s period of [[rotation]]. These orbits occur at a radius of 24,360 [[gigametre|Gm]] (0,1628 [[AU]]) around the [[Sun]], a little less than half of the [[orbital radius]] of [[Mercury (planet)|Mercury]].
===Special classifications===
* '''[[Sun-synchronous orbit]]''': An orbit which combines [[altitude]] and [[inclination]] in such a way that the satellite passes over any given point of the [[planets]]'s surface at the same local [[solar time]]. Such an orbit can place a satellite in constant sunlight and is useful for [[imaging]], [[spy satellite|spy]], and [[weather satellite]]s.
* '''[[Moon orbit]]''': The [[Orbital parameters|orbital characteristics]] of [[earth]]'s [[moon]]. Average [[altitude]] of 384403 kilometres (238857 mi), [[elliptical orbit|elliptical]]-[[inclined orbit]].
=== Pseudo-orbit classifications ===
* '''[[Horseshoe orbit]]''': An [[orbit]] that appears to a ground observer to be orbiting a certain [[planet]] but is actually in [[Co-orbital satellite|co-orbit]] with the [[planet]]. See asteroids [[3753 Cruithne|3753]] (Cruithne) and [[2002 AA29|2002 AA<small><sub>29</sub></small>]].
* '''[[Exo-orbit]]''': A maneuver where a [[spacecraft]] approaches the height of [[orbit]] but lacks the [[velocity]] to sustain it.
** '''[[Suborbital spaceflight]]''': A [[synonym]] for [[exo-orbit]].
* '''[[Lunar transfer orbit]] (LTO)'''
* '''[[Prograde orbit]]''': An [[orbit]] with an inclination of less than 90°. Or rather, an orbit that is in the same direction as the rotation of the primary.
* '''[[Retrograde orbit]]''': An [[orbit]] with an [[inclination]] of more than 90°. Or rather, an orbit counter to the direction of rotation of the planet. Apart from those in [[sun-synchronous orbit]], few satellites are launched into [[retrograde orbit]] because the quantity of fuel required to launch them is much greater than for a [[prograde orbit]]. This is because when the rocket starts out on the ground, it already has an eastward component of [[velocity]] equal to the rotational velocity of the planet at its launch [[latitude]].
*'''[[Halo orbit]]''' and '''[[Lissajous orbit]]''': Orbits "around" [[Lagrangian point]]s.
== Satellite Modules ==
The satellite’s functional versatility is imbedded within its technical components and its operations characteristics. Looking at the “anatomy” of a typical satellite, one discovers two modules.<ref name=Grant&Meadows/> Note that some novel architectural concepts such as [[Fractionated Spacecraft]] somewhat upset this taxonomy.
=== Spacecraft bus or service module ===
This first module consist of five subsystems:
* '''The Structural Subsystems'''
The structural subsystem provides the mechanical base structure, shields the satellite from extreme temperature changes and micro-meteorite damage, and controls the satellite’s spin functions.
* '''The Telemetry Subsystems'''
The telemetry subsystem monitors the on-board equipment operations, transmits equipment operation data to the earth control station, and receives the earth control station’s commands to perform equipment operation adjustments.
* '''The Power Subsystems'''
The power subsystem consists of solar panels and backup batteries that generate power when the satellite passes into the earth’s shadow.
* '''The Thermal Control Subsystems
The thermal control subsystem helps protect electronic equipment from extreme temperatures due to intense sunlight or the lack of sun exposure on different sides of the satellite’s body
* '''The Attitude and Orbit Controlled Control Subsystems
The attitude and orbit controlled subsystem consists of small rocket thrusters that keep the satellite in the correct orbital position and keep antennas positioning in the right directions.
=== Communication Payload ===
The second major module is the communication payload, which is made up of transponders. A transponders is capable of :
* '''Receiving uplinked radio signals from earth satellite transmission stations (antennas).
* '''Amplifying received radio signals
* '''Sorting the input signals and directing the output signals through input/output signal multiplexers to the proper downlink antennas for retransmission to earth satellite receiving stations (antennas).
==Launch-capable countries ==
{{main|Timeline of first orbital launches by nationality}}
This list includes countries with an independent capability to place satellites in orbit, including production of the necessary launch vehicle. Note: many more countries have the capability to design and build satellites — which relatively speaking, does not require much economic, scientific and industrial capacity — but are unable to launch them, instead relying on foreign launch services. This list '''does not''' consider those numerous countries, but only lists those capable of launching satellites indigenously, and the date this capability was first demonstrated. Does not include consortium satellites or multi-national satellites.
{| class="sortable wikitable"
|+ '''First launch by country'''
|- bgcolor=#efefef
! Country || Year of first launch || First satellite
|-
|align="left"| {{flag|Soviet Union}} || 1957 || ''[[Sputnik 1]]''
|-
|align="left"| {{flag|United States}} || 1958 || ''[[Explorer 1]]''
|-
|align="left"| {{flag|France}} || 1965 || ''[[Astérix (satellite)|Astérix]]''
|-
|align="left"| {{flag|Japan}} || 1970 || ''[[Osumi (Satellite)|Osumi]]''
|-
|align="left"| {{flag|China}} || 1970 || ''[[Dong Fang Hong I]]''
|-
|align="left"| {{flag|United Kingdom}} || 1971 || ''[[Prospero X-3]]''
|-
|align="left"| {{flag|India}} || 1980 || ''[[Rohini space satellite|Rohini]]''
|-
|align="left"| {{flag|Israel}} || 1988 ||''[[Ofeq|Ofeq 1]]''
|}
<!-- Please do not add Kazakhstan, see below, and on talk page for details -->
Both [[North Korea]] (1998) and [[Iraq]] (1989) have claimed orbital launches (satellite and warhead accordingly), but these claims are unconfirmed.
In addition to the above, countries such as [[South Africa]], [[Spain]], [[Italy]], [[West Germany]], [[Canada]], [[Australia]], [[Argentina]], [[Egypt]] and private companies such as [[OTRAG]], have developed their own launchers, but have not had a successful launch.
As of 2008, only seven countries from list above ( [[Russia]] and [[Ukraine]] instead of [[USSR]], also [[USA]], [[Japan]], [[China]], [[India]], and [[Israel]]) and one regional organization (the [[European Space Agency]], ESA) have independently launched satellites on their own indigenously developed launch vehicles. (The launch capabilities of the [[United Kingdom]] and [[France]] now fall under the [[ESA]].)
Several other countries, including [[South Korea]], [[Iran]], [[Brazil]], [[Pakistan]], [[Romania]], [[Kazakhstan]], [[Australia]], [[Malaysia]]{{Fact|date=June 2008}} and [[Turkey]], are at various stages of development of their own small-scale launcher capabilities, and seek membership in the club of space powers.
It is scheduled that in early 2008 [[Korea Aerospace Research Institute|South Korea]] will launch a [[KSLV]] rocket (created with assistance of Russia) and become the next space power. [[Iran]] already has successfully tested its own space launch vehicle ([[Kavoshgar 1]]) and is scheduled to put its first domestic satellite ([[Omid (satellite)|Omid 1]]) into orbit within a year from [[February 4]] [[2008]]. It is expected that Brazil and Pakistan will follow in the near future..{{Fact|date=May 2008}}
{| class="sortable wikitable"
|+ '''First launch by country including help of other parties'''<ref>{{citeweb|title=First time in History|url=http://www.tbs-satellite.com/tse/online/thema_first.html|publisher=tbs-satellite.com|accessdate=2008-03-06}}</ref>
|- bgcolor=#efefef
! Country || Year of first launch || First satellite || Payloads in orbit in 2008<ref>{{citeweb|title=SATCAT Boxscore|url=http://www.celestrak.com/satcat/boxscore.asp|publisher=celestrak.com|accessdate=2008-03-05}}</ref>
|-
|align="left"| {{flag|Soviet Union}} || 1957 || ''[[Sputnik 1]]'' || 1398
|-
|align="left"| {{flag|United States}} || 1958 || ''[[Explorer 1]]'' || 1042
|-
|align="left"| {{flag|Canada}} || 1962 || ''[[Alouette 1]]'' || 25
|-
|align="left"| {{flag|Italy}} || 1964 || ''[[San Marco 1]]'' ||14
|-
|align="left"| {{flag|France}} || 1965 || ''[[Astérix (satellite)|Astérix]]'' || 44
|-
|align="left"| {{flag|Australia}} || 1967 || ''[[WRESAT]]'' || 11
|-
|align="left"| {{flag|Germany}} || 1969 || ''[[Azur (satellite)|Azur]]'' ||27
|-
|align="left"| {{flag|Japan}} || 1970 || ''[[Osumi (Satellite)|Osumi]]'' || 111
|-
|align="left"| {{flag|China}} || 1970 || ''[[Dong Fang Hong I]]'' || 64
|-
|align="left"| {{flag|United Kingdom}} || 1971 || ''[[Prospero X-3]]'' || 25
|-
|align="left"| {{flag|Poland}} || 1973 || ''[[Intercosmos#Unmanned_missions|Intercosmos Kopernikus 500]]'' || ?
|-
|align="left"| {{flag|Netherlands}} || 1974 || ''[[ANS (satellite)|ANS]]'' || 5
|-
|align="left"| {{flag|Spain}} || 1974 || ''[[Intasat]]'' || 9
|-
|align="left"| {{flag|India}} || 1975 || ''[[Aryabhata (satellite)|Aryabhata]]'' || 34
|-
|align="left"| {{flag|Indonesia}} || 1976 || ''[[Palapa#Series_A|Palapa A1]]'' ||10
|-
|align="left"| {{flag|Czechoslovakia}} || 1978 || ''[[Magion 1]]'' || 5
|-
|align="left"| {{flag|Bulgaria}} || 1981 || ''[[Intercosmos#Unmanned_missions|Intercosmos 22]]'' ||
|-
|align="left"| {{flag|Brazil}} || 1985 || ''[[Brasilsat A1]]'' ||11
|-
|align="left"| {{flag|Mexico}} || 1985 || ''[[Morelos 1]]'' || 7
|-
|align="left"| {{flag|Sweden}} || 1986 || ''[[Viking (satellite)|Viking]]'' || 11
|-
|align="left"| {{flag|Israel}} || 1988 ||''[[Ofeq|Ofeq 1]]'' || 7
|-
|align="left"| {{flag|Luxembourg}} || 1988 ||''[[Astra 1A]]'' ||15
|-
|align="left"| {{flag|Argentina}} || 1990 ||''[[Lusat]]'' || 10
|-
|align="left"| {{flag|Pakistan}} || 1990 ||''[[Badr-1]]'' ||5
|-
|align="left"| {{flag|South Korea}} || 1992 ||''[[Kitsat A]]'' ||10
|-
|align="left"| {{flag|Portugal}} || 1993 ||''[[PoSAT-1]]'' || 1
|-
|align="left"| {{flag|Thailand}} || 1993 ||''[[Thaicom|Thaicom 1]]'' || 6
|-
|align="left"| {{flag|Turkey}} || 1994 ||''[[Turksat 1B]]'' || 5
|-
|align="left"| {{flag|Chile}} || 1995 ||''[[FASat-Alfa]]'' ||1
|-
|align="left"| {{flag|Malaysia}} || 1996 ||''[[MEASAT]]'' ||4
|-
|align="left"| {{flag|Norway}} || 1997 ||''[[Thor 2]]'' ||3
|-
|align="left"| {{flag|Philippines}} || 1997 ||''[[Mabuhay 1]]'' ||2
|-
|align="left"| {{flag|Egypt}} || 1998||''[[Nilesat 101]]'' || 3
|-
|align="left"| {{flag|Denmark}} || 1999 ||''[[Ørsted (satellite)|Ørsted]]'' ||3
|-
|align="left"| {{flag|South Africa}} || 1999||''[[SUNSAT]]'' ||1
|-
|align="left"| {{flag|Saudi Arabia}} || 2000||''[[Saudisat 1A]]'' || 12
|-
|align="left"| {{flag|United Arab Emirates}} || 2000||''[[Thuraya#Satellites|Thuraya 1]]'' ||3
|-
|align="left"| {{flag|Algeria}} || 2002||''[[Alsat 1]]'' ||1
|-
|align="left"| {{flag|Greece}} || 2003||''[[Hellas Sat 2]]'' || 2
|-
|align="left"| {{flag|Nigeria}} || 2003||''[[Nigeriasat 1]]'' ||2
|-
|align="left"| {{flag|Iran}} || 2005 || ''[[Sina-1]]'' || 1
|-
|align="left"| {{flag|Kazakhstan}} || 2006 || ''[[KazSat|KazSat 1]]'' || 1
|-
|align="left"| {{flag|Colombia}} || 2007 || ''[[Libertad 1]]'' ||1
|-
|align="left"| {{flag|Vietnam}} || 2008 || ''[[VINASAT-1]]'' ||1
|}
While [[Canada]] was the third country to build a satellite which was launched into space,<ref>{{citeweb|title=Canada's Churchill Spaceport|url=http://www.spacetoday.org/Rockets/Spaceports/Canada.html|publisher=spacetoday.org|accessdate=2008-03-06}}</ref> it was launched aboard a U.S. rocket from a U.S. spaceport. The same goes for [[Australia]], who launched on-board a donated Redstone rocket. The first Italian-launched was [[San Marco 1]], launched on [[15 December]], [[1964]] on a U.S. [[Scout rocket]] from Wallops Island (VA,USA) with an Italian Launch Team trained by NASA.<ref>{{citeweb|title=San Marco 1|url=http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1964-084A|publisher=nasa.gov|accessdate=2008-03-05}}</ref> [[Australia]]'s launch project, in November 1967, involved a donated U.S. missile and U. S. support staff as well as a joint launch facility with the [[United Kingdom]].<ref>{{citeweb|title=WRESAT_Australia's_First_Satellite|url=http://homepage.powerup.com.au/~woomera/wresat.htm|publisher=powerup.com.au|accessdate=2008-03-05}}</ref> [[Kazakhstan]] claimed to have made their satellite independently{{Fact|date=May 2008}}, but the satellite was built with Russian help, like Polish and Bulgarian ones earlier.
==Attacks on satellites==
{{ Details|Anti-satellite weapon }}
In recent times satellites have been hacked by militant organisations to broadcast propaganda and to pilfer classified information from military communication networks.<ref>{{citeweb|title=Hack a Satellite while it is in orbit|url=http://blogs.ittoolbox.com/security/dmorrill/archives/hack-a-satellite-while-it-is-in-orbit-15690|publisher=ittoolbox.com|accessdate=2008-03-25}}</ref><ref>{{citeweb|title=AsiaSat accuses Falungong of hacking satellite signals|url=http://www.accessmylibrary.com/coms2/summary_0286-5205866_ITM|publisher=[[Press Trust of India]]|accessdate=2008-03-25}}</ref>
Satellites in low earth orbit have been destroyed by ballistic missiles launched from earth. Both [[Russia]] and the [[United States]] have demonstrated ability to eliminate satellites.<ref name="asat">{{citeweb|title=China Tests Anti-Satellite Weapon, Unnerving U.S.|url=http://www.nytimes.com/2007/01/18/world/asia/18cnd-china.html?_r=1&pagewanted=all&oref=slogin|publisher=nytimes.com|accessdate=2008-03-25}}</ref> In [[2007]] the [[China|Chinese]] military shot down an ageing weather satellite,<ref name="asat"/> followed by the [[US Navy]] shooting down a [[NRO L-21|defunct spy satellite]] in [[February 2008]].<ref>{{citeweb|title=Navy Missile Successful as Spy Satellite Is Shot Down |url=http://www.popularmechanics.com/blogs/science_news/4251430.html|publisher=popularmechanics.com|accessdate=2008-03-25}}</ref>
[[Russia]] and the [[United States]] have also shot down satellites during the [[Cold war]].
===Jamming===
Due to the low received signal strength of satellite transmissions they are prone to [[Radio jamming]] by land-based transmitters. Such jamming is limited to the geographical area within the transmitter's range. GPS satellites are potential targets for jamming,<ref>{{citeweb|title=U.S.-Led Forces Destroy GPS Jamming Systems in Iraq |url=http://www.space.com/news/gps_iraq_030325.html|publisher=space.com|accessdate=2008-03-25}}</ref><ref>{{citeweb|title=Homemade GPS jammers raise concerns|url=http://www.computerworld.com/securitytopics/security/story/0,10801,77702,00.html|publisher=computerworld.com|accessdate=2008-03-25}}</ref> but satellite phone and television signals have also been subjected to jamming.<ref>{{citeweb|title=Iran government jamming exile satellite TV|url=http://www.iranfocus.com/modules/news/article.php?storyid=2852|publisher=iranfocus.com|accessdate=2008-03-25}}</ref><ref>{{citeweb|title=Libya Pinpointed as Source of Months-Long Satellite Jamming in 2006|url=http://www.space.com/spacenews/businessmonday_070409.html|publisher=space.com|accessdate=2008-03-25}}</ref>
==Satellite Services==
* [[Satellite Internet access]]
* [[Satellite phone]]
* [[Satellite radio]]
* [[Satellite television]]
* [[Satellite navigation]]
==See also==
{{Portal | Spaceflight | RocketSunIcon.svg}}
* [[2007 Chinese anti-satellite missile test]]
* [[Footprint (satellite)]]
* [[Fractionated Spacecraft]]
* [[GoldenEye (fictional satellite weapon)]]
* [[International Designator]]
* [[IMINT]]
* [[List of Earth observation satellites]]
* [[Satellite Catalog Number]]
* [[Satellite formation flying]]
* [[Smallsat]]
* [[Space debris]]
* [[USA 193]]
==References==
{{reflist|2}}
==External links==
* [http://dels.nas.edu/basc/earthobservations Earth Observations from Space] A collection of satellite-based images and animations from the National Research Council.
* [http://science.nasa.gov/RealTime/JTrack/3D/JTrack3D.html J-Track 3D] A 3-dimensional display of all active satellites orbiting planet Earth.
* [http://en.satellite.tracks.free.fr Satellite Ground Tracks] Real time satellite's tracks (Full catalog of satellite orbit). {{en icon}} {{de icon}} {{es icon}} {{fr icon}} {{it icon}} {{pt icon}} {{zh icon}}
* [http://www.vega.org.uk/video/programme/12 'Eyes in the Sky' Free video by the Vega Science Trust and the BBC/OU] Satellites and their implications over the last 50 years.
* [http://science.howstuffworks.com/satellite.htm How Stuff Works.com] How satellites work
*[http://www.ucsusa.org/global_security/space_weapons/satellite_database.html UCS Satellite Database] Lists operational satellites currently in orbit around the Earth. Updated quarterly.
*[http://www.satelliteonthenet.co.uk/launch.html Satellite launch schedule]
{{Space-based meteorological observation}}
[[Category:Satellites| ]]
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[[Category:Meteorological data and networks]]
[[Category:Russian inventions]]
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