Intelsat 15, also known as IS-15, is a

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 Ear ...

owned by

Intelsat Intelsat S.A. (formerly INTEL-SAT, INTELSAT, Intelsat) is a multinational satellite services provider with corporate headquarters in Luxembourg and administrative headquarters in Tysons Corner, Virginia, United States. Originally formed as ...

. Intelsat 15 was built by

Orbital Sciences Corporation Orbital Sciences Corporation (commonly referred to as Orbital) was an American company specializing in the design, manufacture, and launch of small- and medium- class space and launch vehicle systems for commercial, military and other governmen ...

, on a

Star-2.4 The STAR-2 Bus is a fully redundant, flight-proven, spacecraft bus designed for geosynchronous missions. It is a satellite platform, designed and developed by Thomas van der Heyden for the Indonesian Cakrawarta satellite program in the early 19 ...

. It is located at 85° E longitude on the geostationary orbit. It was launched from

Baikonur Cosmodrome ''Baiqoñyr ğaryş ailağy'' rus, Космодром Байконур''Kosmodrom Baykonur'' , image = Baikonur Cosmodrome Soyuz launch pad.jpg , caption = The Baikonur Cosmodrome's " Gagarin's Start" Soyu ...

to a

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 ...

on 30 November 2009 by a

Zenit-3SLB The Zenit 3SLB or Zenit-3M is a Ukrainian expendable carrier rocket derived from the Zenit-2SB. It is a member of the Zenit family of rockets, which were designed by the Yuzhnoye Design Office. Produced at Yuzhmash, the rocket is a modified ver ...

launch vehicle. It has 22 active K_u band

transponders In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend of ''transmitter'' and ''responder''. In air navigation or radio frequency identification, a flight tran ...

, plus eight spares. Five of those transponders are owned and operated by

SKY Perfect JSAT Group The SKY Perfect JSAT Group is a Japanese corporate group that claims to be Asia's largest satellite communication and multi-channel pay TV company. It owns the SKY PerfecTV! satellite broadcasting service and the SKY Perfect Well Think content ...

under the name JCSAT-85.

Satellite description

Intelsat 15 is a 3 axis stabilized geostationary

based on the

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- ...

. It weighed at launch, had a dry mass of , and a design life 15 years. It had a power availability dedicated to the payload of 4.6 kW, due to its

multi-junction Multi-junction (MJ) solar cells are solar cells with multiple p–n junctions made of different semiconductor materials. Each material's p-n junction will produce electric current in response to different wavelengths of light. The use of multiple ...

GaAs Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a zinc blende crystal structure. Gallium arsenide is used in the manufacture of devices such as microwave frequency integrated circuits, monolithic microwave integrated ...

solar cell A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.watt hour A kilowatt-hour ( unit symbol: kW⋅h or kW h; commonly written as kWh) is a unit of energy: one kilowatt of power for one hour. In terms of SI derived units with special names, it equals 3.6 megajoules (MJ). Kilowatt-hours are a common bi ...

Li-ion batteries A lithium-ion or Li-ion battery is a type of rechargeable battery which uses the reversible reduction of lithium ions to store energy. It is the predominant battery type used in portable consumer electronics and electric vehicles. It also sees ...

for surviving the solar eclipses. The satellite used a

bipropellant The highest specific impulse chemical rockets use liquid propellants (liquid-propellant rockets). They can consist of a single chemical (a monopropellant) or a mix of two chemicals, called bipropellants. Bipropellants can further be divided into ...

propulsion system with an IHI BT-4 Liquid Apogee Engine for orbit circularization and thrusters and

reaction wheel A reaction wheel (RW) is used primarily by spacecraft for three-axis attitude control, and does not require rockets or external applicators of torque. They provide a high pointing accuracy, and are particularly useful when the spacecraft must be ...

s for station keeping and

attitude control Attitude control is the process of controlling the orientation of an aerospace vehicle with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc. Controlling vehicle ...

. It was filled with enough propellant for 15 years, but due to the efficient launch and transfer 17 are expected. Its payload is composed two deployable dual grid reflectors, plus one deck mounted reflector. They are fed by 22 active K_u band

transponder In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend of ''transmitter'' and ''responder''. In air navigation or radio frequency identification, a flight trans ...

s, plus eight spares. Intelsat uses 17 transponders, which have a bandwidth of twenty 36 MHz

transponder equivalent A communications satellite's transponder is the series of interconnected units that form a communications channel between the receiving and the transmitting antennas. It is mainly used in satellite communication to transfer the received signals. ...

s. Its footprint is arranged in a Russia beam and a Middle East beam.

owns five physical transponders under the name JCSAT-85, four have a bandwidth of 36 MHz and the other one has 72 MHz. JSCAT-85 footprint is arranged in two beams, West IOR Beam, covering middle East and the Arabic Sea, and East IOR Beam, covering the Eastern Asia coast and Pacific Ocean.

History

On April 2, 2007,

JSAT Corporation JSAT Corporation (JSAT) was the first private Japanese satellite operator, which owned the JSAT satellites, as well as operated and partially owned the N-Star with NTT DoCoMo. Its origins can be traced to the funding of Japan Communications ...

(now

) announced an agreement to purchase a payload consisting of five transponders on the yet to be built Intelsat 15. Intelsat and JSAT had already collaborated on the

Horizons-1 Horizons-1, also known as Galaxy 13, is a geostationary communications satellite operated by Intelsat and SKY Perfect JSAT (JSAT) which was designed and manufactured by Boeing on the BSS-601 platform. It has Ku-band and C-band payload and ...

and

Horizons-2 Horizons-2 is a communications satellite owned by Horizons Satellite, a joint venture between SKY Perfect JSAT Group and Intelsat. Its orbital slot is located at 74° west longitude. Launch Horizons-2 was launched from the Guiana Space Centre ...

satellites. The satellite, also known as IS-15, would provide services to the Asia-Pacific, Indian Ocean and Middle East regions from the 85°E longitude on the geostationary orbit, where it would replace

Intelsat 709 Intelsat 709 (also known as IS-709 and Intelsat 7-F9) is a geostationary Communications satellite that was built by Space Systems/Loral (SSL). It is located in the orbital position of 47.5° west longitude. The satellite is owned by Intelsat. ...

. It would have 22 K_u band transponders in total and a design life of 15 years. The JSAT payload would be known as JCSAT-85. On May 1, 2007,

(now

Orbital ATK Northrop Grumman Innovation Systems (NGIS) was a sector (business segment) of Northrop Grumman from 2018 through 2019. It was formed from Orbital ATK Inc. a company which resulted from the merger of Orbital Sciences Corporation and parts of Alli ...

) announced that it had been awarded a contract to manufacture Intelsat 15. It would be based on the

STAR-2 The STAR-2 Bus is a fully redundant, flight-proven, spacecraft bus designed for geosynchronous missions. It is a satellite platform, designed and developed by Thomas van der Heyden for the Indonesian Cakrawarta satellite program in the early 19 ...

, generate 4.6 kW of power for its 22-transponder K_u band payload and had an expected launch date of early 2009. On February 26, 2008,

Sea Launch Sea Launch was a multinational—Norway, Russia, Ukraine, United States—spacecraft launch company founded in 1995 that provided orbital launch services from 1999–2014. The company used a mobile maritime launch platform for equatorial lau ...

announce a contract with Intelsat to launch two satellites manufactured by Orbital Corporation, Intelsat 15 and

Intelsat 16 Intelsat 16 is a communications satellite owned by Intelsat planned to be located at 58° W. L. It was built by Orbital Sciences Corporation Orbital Sciences Corporation (commonly referred to as Orbital) was an American company specializing ...

. The contract was itself a renegotiation for repurpose two already existing reservation by Intelsat with Sea Launch for two satellites to these new spacecraft. They were expected to be launched by the

Land Launch Land Launch refers to a service product of Sea Launch SA. There is no entity or company called Land Launch. Sea Launch created the Land Launch offering to address lighter satellites directly into geosynchronous orbit or into geosynchronous transf ...

service, which used

rockets from the

in Kazakhstan, during 2009. Between October 27 and November 5, 2009 Intelsat 15 was processed in the Baikonur Cosmodrome. On November 6, it was filled with propellant. On November 24, 2009, JSAT announced that the launch of Intelsat 15 was expected on November 29 at 1:00 UTC. But during the launch attempt on November 29, the automatic prelaunch issued an abort command. But the launch committee agreed to make a second attempt on the next day. On November 30, 2009, at 21:00 UTC, the Zenit-3SLB successfully launched Intelsat 15, from

Baikonur Cosmodrome Site 45 Site 45 at the Baikonur Cosmodrome is a launch site used by Zenit rockets. It consists of two pads, one of which is still in use. It has been the launch site for all Soviet and Russian government Zenit launches, along with a commercial launch con ...

. After a six and a half hour mission, the DM-3SLB successfully separated the spacecraft and at 03:28 UTC, first signals from spacecraft were received. The launch put the satellite with margins of its planned

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 ell ...

of 10,286 km, 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 el ...

of 35,790 km and a 12° inclination to the Equator.

References

{{Orbital launches in 2009 Intelsat satellites Communications satellites in geostationary orbit Satellite television Spacecraft launched in 2009 Satellites using the GEOStar bus