Intelsat 15


Intelsat 15, also known as IS-15, is a communications satellite owned by Intelsat. Intelsat 15 was built by Orbital Sciences Corporation, on a Star-2.4.[2] It is located at 85° E longitude on the geostationary orbit. It was launched from Baikonur Cosmodrome to a geosynchronous transfer orbit on 30 November 2009 by a Zenit-3SLB launch vehicle.[3][4] It has 22 active Ku band transponders, plus eight spares. Five of those transponders are owned and operated by SKY Perfect JSAT Group under the name JCSAT-85.[5][2]

Intelsat 15
NamesIS-15 / JSCAT-85
Mission typeCommunications
OperatorIntelsat / SKY Perfect JSAT Group
COSPAR ID2009-067A
SATCAT no.36106
Mission duration15 years
Spacecraft properties
ManufacturerOrbital Sciences
Launch mass2,484 kg (5,476 lb)
Dry mass1,227 kg (2,705 lb)
Power4.6 kW
Start of mission
Launch date21:00, November 30, 2009 (UTC) (2009-11-30T21:00Z)
Launch siteBaikonur 45/1
ContractorLand Launch
Orbital parameters
Reference systemGeocentric
Longitude85° east
Semi-major axis42,164.0 km (26,199.5 mi)
Perigee altitude35,786.0 km (22,236.4 mi)
Apogee altitude35,800.9 km (22,245.6 mi)
Period1,436.1 minutes
EpochMay 07, 2018[1]
Band22 (+8 spares) Ku band
Coverage areaRussia, Near East, Indian Ocean

Satellite descriptionEdit

Intelsat 15 is a 3 axis stabilized geostationary communications satellite based on the Star-2.4 satellite bus. It weighted 2,484 kg (5,476 lb) at launch, had a dry mass of 1,227 kg (2,705 lb), and a design life 15 years.[6][7] It had a power availability dedicated to the payload of 4.6 kW, due to its Multi-junction GaAs solar cells. It also had two 4840 watt hour Li-ion batteries for surviving the solar eclipses.[6]

The satellite used a bipropellant propulsion system with an IHI BT-4 Liquid Apogee Engine for orbit circularization and thrusters and reaction wheels for station keeping and attitude control.[6][2] It was filled with enough propellant for 15 years, but due to the efficient launch and transfer 17 are expected.[2]

Its payload is composed two 2.3 m (7 ft 7 in) deployable dual grid reflectors, plus one 1.4 m (4 ft 7 in) deck mounted reflector. They are fed by 22 active Ku band transponders, plus eight spares. Intelsat uses 17 transponders, which have a bandwidth of twenty 36 MHz transponder equivalents.[6][2] Its footprint is arranged in a Russia beam and a Middle East beam.[8] SKY Perfect JSAT Group 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.[5][9]


On April 2, 2007, JSAT Corporation (now SKY Perfect JSAT Group) 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 and Horizons-2 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. It would have 22 Ku band transponders in total and a design life of 15 years.[10] The JSAT payload would be known as JCSAT-85.[9]

On May 1, 2007, Orbital Sciences Corporation (now Orbital ATK) announced that it had been awarded a contract to manufacture Intelsat 15. It would be based on the STAR-2 satellite bus, generate 4.6 kW of power for its 22-transponder Ku band payload and had an expected launch date of early 2009.[11]

On February 26, 2008, Sea Launch announce a contract with Intelsat to launch two satellites manufactured by Orbital Corporation, Intelsat 15 and Intelsat 16. 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 service, which used Zenit-3SLB rockets from the Baikonur Cosmodrome in Kazakhstan, during 2009.[12]

Between October 27 and November 5, 2009 Intelsat 15 was processed in the Baikonur Cosmodrome. On November 6, it was filled with propellant.[13] On November 24, 2009, JSAT announced that the launch of Intelsat 15 was expected on November 29 at 1:00 UTC.[14] But during the launch attempt on November 29, the automatic prelaunch issued an abort command.[15][13] But the launch committee agreed to make a second attempt on the next day.[13]

On November 30, 2009, at 21:00 UTC, the Zenit-3SLB successfully launched Intelsat 15, from Baikonur Cosmodrome Site 45. 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.[16][17] The launch put the satellite with margins of its planned geosynchronous transfer orbit with a perigee of 10,286 km, an apogee of 35,790 km and a 12° inclination to the Equator.[13]


  1. ^ "Intelsat 15". Retrieved May 7, 2018.
  2. ^ a b c d e Krebs, Gunter Dirk (2016-04-21). "Intelsat 15 (JCSat 85)". Gunter's Space Page. Retrieved 2016-09-16.
  3. ^ "Intelsat 15". NASA Space Science Data Coordinated Archive. August 23, 2016. Retrieved 2016-09-16.
  4. ^ "Intelsat 15". NASA Space Science Data Coordinated Archive/Orbital Information. August 23, 2016. Retrieved 2016-09-16.
  5. ^ a b "Who we are". SKY Perfect JSAT Group. 2012-08-03. Archived from the original (PDF) on 2016-09-08. Retrieved 2016-09-16.
  6. ^ a b c d "Intelsat 15 Fact Sheet" (PDF). Orbital ATK. 2015. Retrieved 2016-09-16.
  7. ^ "Intelsat 15". Retrieved 2016-09-16.
  8. ^ "Intelsat 15 at 85° E". Intelsat. Retrieved 2016-09-16.
  9. ^ a b "JCSAT-85". SKY Perfect JSAT Group. Retrieved 2016-09-16.
  10. ^ "JSAT Reaches Agreement to Own Transponders on Intelsat 15 Satellite". JSAT Corporation. April 2, 2007. Archived from the original on 2007-12-25. Retrieved 2016-09-19.
  11. ^ "Orbital Awarded New Contract For IS-15 Commercial Communications Satellite By Intelsat". Orbital Sciences Corporation. May 1, 2007. Archived from the original on 2007-07-08. Retrieved 2016-09-19.
  12. ^ "Sea Launch signs with Intelsat for two Land Launch Missions". Sea Launch. February 26, 2008. Archived from the original on 2016-09-19. Retrieved 2016-09-19.
  13. ^ a b c d "Land Launch Project – Chronology of Launches – INTELSAT 15 Launch". RSC Energia. Archived from the original on 2016-03-26. Retrieved 2016-09-19.
  14. ^ "Notice Regarding Launch Schedule for the Intelsat 15 Satellite" (PDF). SKY Perfect JSAT Group. November 24, 2009. Archived from the original (PDF) on 2016-09-19. Retrieved 2016-09-19.
  15. ^ "Notice Regarding Postponed Launch of the Intelsat 15 Satellite" (PDF). SKY Perfect JSAT Group. November 30, 2009. Archived from the original (PDF) on 2016-09-19. Retrieved 2016-09-19.
  16. ^ "Land Launch Successfully Deploys Intelsat 15 Satellite to Orbit". Sea Launch. November 30, 2009. Archived from the original on 2016-09-19. Retrieved 2016-09-19.
  17. ^ "Notice Regarding Successful Launch of the Intelsat 15 Satellite" (PDF). SKY Perfect JSAT Group. December 1, 2009. Archived from the original (PDF) on 2016-09-19. Retrieved 2016-09-19.