INSAT-4B was an Indian

communications satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. C ...

which forms part of the

Indian National Satellite System The Indian National Satellite System or INSAT, is a series of multipurpose geostationary satellites launched by ISRO to satisfy the telecommunications, broadcasting, meteorology, and search and rescue operations. Commissioned in 1983, INSAT is ...

. Launched in 2007, it was placed in

geostationary orbit A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitud ...

at a longitude of 93.48° East. Built by the

Indian Space Research Organisation The Indian Space Research Organisation (ISRO; ) is the national space agency of India, headquartered in Bengaluru. It operates under the Department of Space (DOS) which is directly overseen by the Prime Minister of India, while the Chairman ...

, INSAT-4B is based upon the

I-3K I-3K or the INSAT 3000 is a satellite bus developed by Indian Space Research Organisation (ISRO), and marketed by Antrix Corporation and New Space India Ltd. It is the standard bus for 3,000-kg class satellites; the 'I' in I-3K stands for INSAT, ...

satellite bus A satellite bus (or spacecraft bus) is the main body and structural component of a satellite or spacecraft, in which the payload and all scientific instruments are held. Bus-derived satellites are opposed to specially produced satellites. Bus-d ...

. It had a mass at launch of , with a dry mass of and was expected to operate for twelve years. Two

solar array A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and co ...

s power the satellite, while its communications payload consists of twelve C and twelve transponders.

Arianespace Arianespace SA is a French company founded in 1980 as the world's first commercial launch service provider. It undertakes the operation and marketing of the Ariane programme. The company offers a number of different launch vehicles: the heavy ...

was contracted to launch INSAT-4B using an Ariane 5 ECA carrier rocket. The launch occurred on 11 March 2007 at 22:03 UTC, from

ELA-3 ELA-3 (french: Ensemble de Lancement Ariane 3, lit=Ariane Launch Complex 3), is a launch pad and associated facilities at the Centre Spatial Guyanais in French Guiana. ELA-3 is operated by Arianespace as part of the expendable launch system f ...

Kourou Kourou () is a commune in French Guiana, an overseas region and department of France in South America. Kourou is famous for being the location of the Guiana Space Centre, the main spaceport of France and the European Space Agency (ESA). It i ...

. The

Skynet 5A Skynet 5A is the first in a series of new-generation Skynet military communications satellites, used by the British Ministry of Defence. It was launched aboard an Ariane 5 carrier rocket at 22:03 GMT on 11 March 2007. Launch Skynet 5A was one ...

military communications satellite for the British

Ministry of Defence {{unsourced, date=February 2021 A ministry of defence or defense (see spelling differences), also known as a department of defence or defense, is an often-used name for the part of a government responsible for matters of defence, found in states ...

was launched aboard the same rocket. INSAT-4B was successfully inserted into

geosynchronous transfer orbit A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellites that are destined for geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into a GTO as an intermediate step f ...

, from which it raised itself into geostationary orbit using a liquid-fuelled

apogee motor An apogee kick motor (AKM) is a rocket motor that is regularly employed on artificial satellites to provide the final impulse to change the trajectory from the transfer orbit into its final (most commonly circular) orbit. For a satellite laun ...

. It received the

International Designator The International Designator, also known as COSPAR ID, is an international identifier assigned to artificial objects in space. It consists of the launch year, a three-digit incrementing launch number of that year and up to a three-letter code repr ...

2007-007A and

Satellite Catalog Number The Satellite Catalog Number (SATCAT, also known as NORAD (North American Aerospace Defense) Catalog Number, NORAD ID, USSPACECOM object number or simply catalog number, among similar variants) is a sequential nine-digit number assigned by the Un ...

30793. As of 11 November 2013, it is in an orbit with a

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ellip ...

of , an

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ellip ...

of ,

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...

of 0.07 degrees and an

orbital period The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets ...

of 23.93 hours.

Partial power failure

On 10 July 2010 INSAT-4B suffered a disruption in power supply from one of the two solar panels, rendering half of its transponder capacity useless. After review the cause of malfunction was found out to be electric arcing in slip ring of one of the solar panels. Similar partial power supply failure also affected Eutelsat W2M now known as

Afghansat 1 Afghansat 1 (Pashto: افغان سټ یو, Persian: افغان‌ست 1), formerly named Eutelsat W2M, Eutelsat 48B, Eutelsat 28B is a telecommunications satellite operated by Afghanistan's Ministry of Communications and Information Technology. ...

and caused delay in launch of

GSAT-8 GSAT-8 or INSAT-4G is communication satellite. It was constructed by the Indian Space Research Organisation, as part of INSAT system. GSAT-8 was launched on May 21, 2011, from Kourou, French Guiana. The rocket, an Ariane 5 was the carrier, marke ...

due to required design changes in relevant power systems of satellite bus.

Relocation

On 11 November 2017, INSAT-4B maneuvered to lower its altitude and drifted eastward to reach new slot at 111.2°E on 18 December 2017. On 20 August 2019, altitude of INSAT-4B was raised and it was relocated to new 83°E slot on 12 October 2019. On 15 February 2020, altitude of INSAT-4B was lowered and it was relocated to new 85.5°E slot on 20 February 2020.

Decommissioning

Towards the end of its life INSAT-4B was placed in

Graveyard orbit A graveyard orbit, also called a junk orbit or disposal orbit, is an orbit that lies away from common operational orbits. One significant graveyard orbit is a supersynchronous orbit well beyond geosynchronous orbit. Some satellites are moved int ...

under post mission disposal procedure and subsequently decommissioned on 24 January 2022, in accordance with the space debris mitigation guidelines recommended by UN and the Inter Agency Space Debris Coordination Committee (IADC).

References

{{Orbital launches in 2007 Spacecraft launched in 2007 INSAT satellites 2007 in India Spacecraft decommissioned in 2022