Geostationary orbit

GeostationaryGEOgeostationary satelliteClarke Beltgeo-stationarygeo-stationary orbitgeostationary beltGeostationary Earth Orbitgeo­stationary orbitGeostationary orbit (GEO)
A geostationary orbit, often referred to as a geosynchronous equatorial orbit (GEO), is a circular geosynchronous orbit 35786 km above Earth's equator and following the direction of Earth's rotation.wikipedia
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Communications satellite

satellitesatellite communicationscommunication satellite
Communications satellites and weather satellites are often placed in geostationary orbits, so that the satellite antennae (located on Earth) that communicate with them do not have to rotate to track them, but can be pointed permanently at the position in the sky where the satellites are located.
Many are in geostationary orbit 22,200 mi above the equator, so that the satellite appears stationary at the same point in the sky, so the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track it.

Geosynchronous orbit

geosynchronousGEOGSO
A geostationary orbit, often referred to as a geosynchronous equatorial orbit (GEO), is a circular geosynchronous orbit 35786 km above Earth's equator and following the direction of Earth's rotation.
A special case of geosynchronous orbit is the geostationary orbit, which is a circular geosynchronous orbit in Earth's equatorial plane (that is, directly above the Equator).

Weather satellite

satellitemeteorological satelliteWeather
Communications satellites and weather satellites are often placed in geostationary orbits, so that the satellite antennae (located on Earth) that communicate with them do not have to rotate to track them, but can be pointed permanently at the position in the sky where the satellites are located.
Satellites can be polar orbiting, covering the entire Earth asynchronously, or geostationary, hovering over the same spot on the equator.

Satellite dish

satellite dishesdishsatellite antenna
Communications satellites and weather satellites are often placed in geostationary orbits, so that the satellite antennae (located on Earth) that communicate with them do not have to rotate to track them, but can be pointed permanently at the position in the sky where the satellites are located.
The term most commonly means a dish used by consumers to receive direct-broadcast satellite television from a direct broadcast satellite in geostationary orbit.

Geostationary Ocean Color Imager

GOCI
Using this characteristic, ocean-color monitoring satellites with visible and near-infrared light sensors (e.g. GOCI) can also be operated in geostationary orbit in order to monitor sensitive changes of ocean environments.
Geostationary Ocean Color Imager (GOCI, ), is the world’s first geostationary orbit satellite image sensor in order to observe or monitor an ocean-color around the Korean Peninsula [1][2].

Arthur C. Clarke

Sir Arthur C. ClarkeClarkeSir Arthur Clarke
British science fiction author Arthur C. Clarke disseminated the idea widely, with more details on how it would work, in a 1945 paper entitled "Extra-Terrestrial Relays — Can Rocket Stations Give Worldwide Radio Coverage?", published in Wireless World magazine.
In 1945, he proposed a satellite communication system using geostationary orbits.

Geostationary transfer orbit

geosynchronous transfer orbitGTOtransfer
A geostationary transfer orbit is used to move a satellite from low Earth orbit (LEO) into a geostationary orbit.
A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a Hohmann transfer orbit—an elliptical orbit used to transfer between two circular orbits of different radii in the same plane—used to reach geosynchronous or geostationary orbit using high-thrust chemical engines.

Syncom

Syncom 2LEASATSyncom IV-1
The first satellite placed into a geostationary orbit was the Syncom-3, launched by a Delta D rocket in 1964.
Syncom 3, launched in 1964, was the world's first geostationary satellite.

Meteosat

MSG-4MTGMSG
Meteosat, launched by the European Space Agency and operated by the European Weather Satellite Organization, EUMETSAT
The Meteosat series of satellites are geostationary meteorological satellites operated by EUMETSAT under the Meteosat Transition Programme (MTP) and the Meteosat Second Generation (MSG) program.

Indian National Satellite System

INSATINSAT-1BINSAT 4B
India's INSAT series
or INSAT, is a series of multipurpose geo-stationary satellites launched by ISRO to satisfy the telecommunications, broadcasting, meteorology, and search and rescue operations.

Circular orbit

circularcircular orbitscircular Keplerian orbits
A geostationary orbit, often referred to as a geosynchronous equatorial orbit (GEO), is a circular geosynchronous orbit 35786 km above Earth's equator and following the direction of Earth's rotation.
Maneuvering into a large circular orbit, e.g. a geostationary orbit, requires a larger delta-v than an escape orbit, although the latter implies getting arbitrarily far away and having more energy than needed for the orbital speed of the circular orbit.

Ocean color

ocean-coloroceanocean's color
Using this characteristic, ocean-color monitoring satellites with visible and near-infrared light sensors (e.g. GOCI) can also be operated in geostationary orbit in order to monitor sensitive changes of ocean environments.
Several new ocean-colour sensors have recently been launched, including the Indian Ocean Colour Monitor (OCM-2) on-board ISRO's Oceansat-2 satellite and the Korean Geostationary Ocean Color Imager (GOCI), which is the first ocean colour sensor to be launched on a geostationary satellite, and Visible Infrared Imager Radiometer Suite (VIIRS) aboard NASA's Suomi NPP.

Delta (rocket family)

DeltaDelta rocketDelta G
The first satellite placed into a geostationary orbit was the Syncom-3, launched by a Delta D rocket in 1964.
Syncom 3, the first geostationary communications satellite

Geostationary Operational Environmental Satellite

GOESGOES-RGOES-S
the United States GOES
Designed to operate in geostationary orbit 35790 km above the Earth, the GOES spacecraft continuously view the continental United States, the Pacific and Atlantic Oceans, Central America, South America, and southern Canada.

Low Earth orbit

Low EarthLEOlow-Earth orbit
A geostationary transfer orbit is used to move a satellite from low Earth orbit (LEO) into a geostationary orbit.
Higher orbits include medium Earth orbit (MEO), sometimes called intermediate circular orbit (ICO), and further above, geostationary orbit (GEO).

Latency (engineering)

latencylow latencylow-latency
Satellites in geostationary orbits are far enough away from Earth that communication latency becomes significant — about a quarter of a second for a trip from one ground-based transmitter to the satellite and back to another ground-based transmitter; close to half a second for a round-trip communication from one Earth station to another and then back to the first.
Satellites in geostationary orbits are far enough away from Earth that communication latency becomes significant — about a quarter of a second for a trip from one ground-based transmitter to the satellite and back to another ground-based transmitter; close to half a second for two-way communication from one Earth station to another and then back to the first.

Orbital period

periodsynodic periodsynodic
A geostationary orbit is a particular type of geosynchronous orbit, which has an orbital period equal to Earth's rotational period, or one sidereal day (23 hours, 56 minutes, 4 seconds).
Geosynchronous orbit derivation

Orbit

orbitsorbital motionplanetary motion
The first appearance of a geostationary orbit in popular literature was in the first Venus Equilateral story by George O. Smith, but Smith did not go into details.
Both geosynchronous orbit (GSO) and geostationary orbit (GEO) are orbits around Earth matching Earth's sidereal rotation period. All geosynchronous and geostationary orbits have a semi-major axis of 42164 km. All geostationary orbits are also geosynchronous, but not all geosynchronous orbits are geostationary. A geostationary orbit stays exactly above the equator, whereas a geosynchronous orbit may swing north and south to cover more of the Earth's surface. Both complete one full orbit of Earth per sidereal day (relative to the stars, not the Sun).

Molniya orbit

Molniyahighly elliptical orbitMolniya orbit satellite
Because of this, some Russian communication satellites have used elliptical Molniya and Tundra orbits, which have excellent visibility at high latitudes.
Geostationary orbits, which are necessarily inclined over the equator, can only view these regions from a low angle, and are unable to view latitudes above 81 degrees.

Orbital station-keeping

station keepingstationkeepingstation-keeping
To correct for this orbital perturbation, regular orbital stationkeeping maneuvers are necessary, amounting to a delta-v of approximately 50 m/s per year.
For geostationary spacecraft the inclination change caused by the gravitational forces of the Sun & Moon must be counteracted by a rather large expense of fuel, as the inclination should be kept sufficiently small for the spacecraft to be tracked by a non-steerable antenna.

European Organisation for the Exploitation of Meteorological Satellites

EUMETSATEuropean Organization for the Exploitation of Meteorological Satellites EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites)
Meteosat, launched by the European Space Agency and operated by the European Weather Satellite Organization, EUMETSAT
While geostationary satellites provide a continuous view of the earth disc from a stationary position in space, the instruments on polar-orbiting satellites, flying at a much lower altitude, provide more precise details about atmospheric temperature and moisture profiles, although with less frequent global coverage.

Tundra orbit

TundraTundra elliptical orbit
Because of this, some Russian communication satellites have used elliptical Molniya and Tundra orbits, which have excellent visibility at high latitudes.
An argument of perigee of 0° or 180° would cause the satellite to dwell over the equator, but there would be little point to this as this could be better done with a conventional geostationary orbit.

Space elevator

orbital elevatorspace elevatorsorbital elevators
Space elevator
An Earth-based space elevator would consist of a cable with one end attached to the surface near the equator and the other end in space beyond geostationary orbit (35,786 km altitude).

Graveyard orbit

disposal orbitjunk orbitabove its previous orbit
The transponders and other onboard systems generally outlive the thruster fuel and, by stopping N–S station keeping, some satellites can continue to be used in inclined orbits (where the orbital track appears to follow a figure-eight loop centred on the equator), or else be elevated to a "graveyard" disposal orbit.
De-orbiting a geostationary satellite requires a delta-v of about 1500 m/s, whereas re-orbiting it to a graveyard orbit only requires about 11 m/s.