Galaxy 11
Encyclopedia
Galaxy 11 is an American geostationary communications satellite
which is operated by Intelsat
. It is located in geostationary orbit
at a longitude
of 32.8 degrees east, where it serves as a backup to the Intelsat 802 spacecraft. It was originally operated at 99° West and later spent most of its operational life at 91° West, from where it was used to provide communications services to Brazil
and North America
.
Galaxy 11 was built for PanAmSat
by Hughes Space and Communications
, and is based around the HS-702 satellite bus
. It was the first HS-702 to be launched, and the first satellite to be equipped with an XIPS propulsion system. It carries 24 G/H band and 40 J band (IEEE C and s respectively) transponder
s, and at launch it had a mass of 4477 kilograms (9,870.1 lb), with an expected operational lifespan of around 15 years.
As the first HS-702 to fly, Galaxy 11 was one of the six which were launched before a design flaw in the type's solar arrays was discovered. Solar concentrators, used to increase the amount of sunlight falling on the arrays, were fogging up due to vapours emitted by the satellite. This reduces the output of the solar arrays, and is expected to result in a reduced operational lifespan. Following the discovery of the fault, US$130 million insurance was claimed on the satellite. The satellite was transferred to Intelsat when it merged with PanAmSat in 2006.
The launch of Galaxy 11 was conducted by Arianespace
, using an Ariane 44L
carrier rocket flying from ELA-2
at the Guiana Space Centre. The launch occurred at 00:50 GMT on 22 December 1999. It successfully placed Galaxy 11 into a geosynchronous transfer orbit, from which it raised itself to geostationary orbit by means of an onboard R-4D apogee motor. Its insertion into geosynchronous orbit occurred at 16:30 on 2 January 2000. The satellite was originally scheduled to be launched by Sea Launch
, on the maiden flight of the Zenit-3SL
, however the contract was transferred to Arianespace, and Sea Launch replaced Galaxy 11 with a DemoSat
for their maiden flight.
Communications satellite
A communications satellite is an artificial satellite stationed in space for the purpose of telecommunications...
which is operated by Intelsat
Intelsat
Intelsat, Ltd. is a communications satellite services provider.Originally formed as International Telecommunications Satellite Organization , it was—from 1964 to 2001—an intergovernmental consortium owning and managing a constellation of communications satellites providing international broadcast...
. It is located in geostationary orbit
Geostationary orbit
A geostationary orbit is a geosynchronous orbit directly above the Earth's equator , with a period equal to the Earth's rotational period and an orbital eccentricity of approximately zero. An object in a geostationary orbit appears motionless, at a fixed position in the sky, to ground observers...
at a longitude
Longitude
Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees, minutes and seconds, and denoted by the Greek letter lambda ....
of 32.8 degrees east, where it serves as a backup to the Intelsat 802 spacecraft. It was originally operated at 99° West and later spent most of its operational life at 91° West, from where it was used to provide communications services to Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
and North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
.
Galaxy 11 was built for PanAmSat
PanAmSat
The former PanAmSat Corporation founded in 1984 by Reynold Anselmo, was a satellite service provider headquartered in Greenwich, Connecticut. It operated a fleet of communications satellites used by the entertainment industry, news agencies, internet service providers, government agencies, and...
by Hughes Space and Communications
Boeing Satellite Development Center
The Boeing Satellite Development Center is a major business unit of Boeing Defense, Space & Security. It brought together Boeing satellite operations with that of GM Hughes Electronics' Space and Communications division.-History:...
, and is based around the HS-702 satellite bus
Satellite bus
A satellite bus or spacecraft bus is the general model on which multiple-production satellite spacecraft are often based. The bus is the infrastructure of a spacecraft, usually providing locations for the payload .They are most commonly used for geosynchronous satellites, particularly...
. It was the first HS-702 to be launched, and the first satellite to be equipped with an XIPS propulsion system. It carries 24 G/H band and 40 J band (IEEE C and s respectively) transponder
Transponder
In telecommunication, the term transponder has the following meanings:...
s, and at launch it had a mass of 4477 kilograms (9,870.1 lb), with an expected operational lifespan of around 15 years.
As the first HS-702 to fly, Galaxy 11 was one of the six which were launched before a design flaw in the type's solar arrays was discovered. Solar concentrators, used to increase the amount of sunlight falling on the arrays, were fogging up due to vapours emitted by the satellite. This reduces the output of the solar arrays, and is expected to result in a reduced operational lifespan. Following the discovery of the fault, US$130 million insurance was claimed on the satellite. The satellite was transferred to Intelsat when it merged with PanAmSat in 2006.
The launch of Galaxy 11 was conducted by Arianespace
Arianespace
Arianespace SA is a French company founded in 1980 as the world's first commercial space transportation company. It undertakes the production, operation, and marketing of the Ariane 5 rocket launcher as part of the Ariane programme....
, using an Ariane 44L
Ariane 4
Ariane 4 was an expendable launch system, designed by the Centre National d'Etudes Spatiales and manufactured and marketed by its subsidiary Arianespace. Ariane 4 was justly known as the ‘workhorse’ of the Ariane family. Since its first flight on 15 June 1988 until the last, on 15 February 2003, it...
carrier rocket flying from ELA-2
ELA-2
ELA-2, short for Ensemble de Lancement Ariane 2 , was a launch pad at the Centre Spatial Guyanais in French Guiana. It was used by Arianespace for all 116 Ariane 4 launches between 1988 and 2003. Following the retirement of the Ariane 4 in favour of the Ariane 5, ELA-2 was deactivated...
at the Guiana Space Centre. The launch occurred at 00:50 GMT on 22 December 1999. It successfully placed Galaxy 11 into a geosynchronous transfer orbit, from which it raised itself to geostationary orbit by means of an onboard R-4D apogee motor. Its insertion into geosynchronous orbit occurred at 16:30 on 2 January 2000. The satellite was originally scheduled to be launched by Sea Launch
Sea Launch
Sea Launch is a spacecraft launch service that uses a mobile sea platform for equatorial launches of commercial payloads on specialized Zenit 3SL rockets...
, on the maiden flight of the Zenit-3SL
Zenit-3SL
The Zenit-3SL is an expendable carrier rocket operated by Sea Launch. First flown in 1999, it has been launched 30 times, with two failures and one partial failure. It is a member of the Zenit family of rockets, and is built by the Yuzhnoye Design Bureau. RKK Energia produces the Block DM-SL upper...
, however the contract was transferred to Arianespace, and Sea Launch replaced Galaxy 11 with a DemoSat
DemoSat
A DemoSat is a boilerplate spacecraft used to test a carrier rocket without risking a real satellite on the launch. They are most commonly flown on the maiden flights of rockets, but have also been flown on return-to-flight missions after launch failures...
for their maiden flight.