A geosynchronous orbit is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds. The synchronization of rotation and orbital period means that, for an observer on Earth's surface, an object in geosynchronous orbit returns to exactly the same position in the sky after a period of one sidereal day. Over the course of a day, the object's position in the sky may remain still or trace out a path, typically in a figure-8 form, whose precise characteristics depend on the orbit's inclination and eccentricity. A circular geosynchronous orbit has a constant altitude of 35,786 km (22,236 mi).
A geostationary orbit, also referred to as a geosynchronous equatorial orbit (GEO), is a circular geosynchronous orbit 35,786 km (22,236 mi) in altitude above Earth's equator, 42,164 km (26,199 mi) in radius from Earth's center, and following the direction of Earth's rotation.
In space mission design, a geostationary transfer orbit (GTO) or geosynchronous transfer orbit is a highly elliptical type of geocentric orbit, usually with a perigee as low as low Earth orbit (LEO) and an apogee as high as geostationary orbit (GEO). Satellites that are destined for geosynchronous orbit (GSO) or GEO are often put into a GTO as an intermediate step for reaching their final orbit. Manufacturers of launch vehicles often advertise the amount of payload the vehicle can put into GTO.
The Guiana Space Centre, also called Europe's Spaceport, is a spaceport to the northwest of Kourou in French Guiana, an overseas region of France in South America. Kourou is located approximately 500 kilometres north of the equator at a latitude of 5°. In operation since 1968, it is a suitable location for a spaceport because of its near equatorial location and open sea to the east and north.
AMOS-2 is an Israeli commercial second generation communication satellite, part of the AMOS series of satellites. The satellite was positioned at 4° West longitude in the geostationary orbit. Transmission and communication services given by this satellite include: direct distribution of television and radio translations to communication centers, distribution of internet services, data transmissions to communication networks. The new satellite, like its predecessor, will be positioned 36,000 kilometers above the Earth, and it will lie close to AMOS-1, so that the two can share a single space antenna.
Optus D3 is an Australian geostationary communications satellite, which is operated by Optus and provides communications services to Australasia. D3 was the third Optus-D satellite to be launched. It is a 2,401-kilogram (5,293 lb) satellite, which was constructed by Orbital Sciences Corporation based on the Star-2.4 satellite bus, with the same configuration as the earlier Optus D2 satellite.
Eutelsat 113 West A, formerly Satmex-6, is a geostationary communications satellite which is operated by Eutelsat. Originally built for Mexico's Satmex, it was launched in 2006. The satellite was acquired by Eutelsat in its 2014 merger with Satmex, and renamed Eutelsat 113 West A in May. It is used to provide communications services to the Americas, Hawaii and the Caribbean.
Arabsat-5A is a Saudi Arabian communications satellite operated by Arabsat. It will be used to provide television, internet and telephone services to Arabia, Africa and Europe.
INSAT-3A, a multipurpose satellite built by ISRO was launched by Ariane in April 2003. It is located at 93.5 degree East longitude. It is third satellite in INSAT-3 series after INSAT-3B & INSAT-3C. Built at a cost of $53 mn, it provides communication, weather, and search and rescue services.
ARSAT-1 is a geostationary communications satellite operated by AR-SAT and built by the Argentine company INVAP. ARSAT-1 was launched into orbit on October 16, 2014, from French Guiana alongside Intelsat-30 satellite using an Ariane 5 rocket. It is expected to be located at 72° West longitude geostationary slot. ARSAT-1 is the first geostationary satellite built in Latin America. Total cost of the satellite is 270 million US dollars.
EchoStar XVII or EchoStar 17, also known as Jupiter 1, is an American geostationary high throughput communications satellite which is operated by Hughes Network Systems, a subsidiary of EchoStar. It is positioned in geostationary orbit at a longitude of 107.1° West, from where it is used for satellite internet access over HughesNet.
Inmarsat-4A F4, also known as Alphasat and Inmarsat-XL, is a large geostationary communications I-4 satellite operated by United Kingdom-based Inmarsat in partnership with the European Space Agency. Launched in 2013, it is used to provide mobile communications to Africa and parts of Europe and Asia.
Eutelsat I F-1, also known as European Communications Satellite 1 (ECS-1) is a decommissioned communications satellite operated by the European Telecommunications Satellite Organisation (Eutelsat). Launched in 1983, it was operated in geostationary orbit at a longitude of 13° East, before moving to several other locations later in its operational life, before it was finally decommissioned in 1996. It was the first of five satellites launched to form the first-generation Eutelsat constellation.
ARSAT-2 is a geostationary communications satellite operated by ARSAT and built by the Argentine company INVAP. It was launched from French Guiana alongside Sky Muster satellite using an Ariane 5ECA rocket on September 30, 2015 at 20:30hs UTC, becoming the 400th satellite to be launched by Arianespace. It is licensed to be located at 81° West longitude geostationary slot. ARSAT-2 is the second geostationary satellite built in Argentina, after ARSAT-1. Structurally and mechanically it is a copy of the ARSAT-1, the only difference being the payload and thus it has different antenna configuration.
The Sky Muster satellites are two geostationary (GEO) communications satellites operated by NBN Co Limited and built by SSL. They were launched in 2015 and 2016 to provide fast broadband in areas where NBN didn't want to either lay fiber or install enough wireless antennas and offshore. The satellites are positioned 35,786 kilometres (22,236 mi) above the equator, north of Australia. They provide download speeds to users of up to 100 Mbit/s, and upload speeds of 10 Mbit/s in a best-case scenario.
Eutelsat 8 West B is a geostationary communications satellite. Operated by Eutelsat, it provides direct-to-home (DTH) broadcasting services from geostationary orbit. The satellite is part of Eutelsat's constellation at a longitude of 8° West. Eutelsat announced the order of a new Spacebus-4000C3 satellite bus from Thales Alenia Space in October 2012.
NSS-806, before Intelsat 806, is a communications satellite originally operated by Intelsat. Launched in 1998 it was operated in geostationary orbit at a longitude of 47 degrees west for around 15 years. It is currently located in the orbital position of 47.5 degrees west longitude, was initially operated by Intelsat, orbited at 40.5 degrees west, and was purchased by SES World Skies.
SaudiGeoSat 1/HellasSat 4, also known as SaudiGeoSat 1/HellasSat 4, is a Saudi and Greek geostationary communication satellite of King Abdulaziz City for Science and Technology (KACST) and HellasSat. It was built by Lockheed Martin and was launched on 5 February 2019 on board Ariane flight VA247.
HYLAS-4 is a telecommunications satellite owned and operated by Avanti Communications and manufactured by Orbital ATK that was launched by an Ariane 5 rocket on 5 April 2018.
The Hispasat 1A was the first communications satellite operated by the Spanish company Hispasat. The satellite covered communications over the Atlantic Ocean for both civilian and military customers. Together with the later Hispasat 1B it formed the first European constellation operating over the New World. Its service life ended in 2003.
