JCSAT-4

JCSAT-4

Names	JCSAT-4 (1995–1997) JCSAT-R (1997–2009) Intelsat 26 (2009–present)
Mission type	Communications
Operator	JSAT/Intelsat
COSPAR ID	1997-007A
SATCATno.	24732
Mission duration	12 years (planned)
Spacecraft properties
Spacecraft	JCSAT-4
Spacecraft type	JCSAT
Bus	HS-601
Manufacturer	Hughes
Launch mass	3,105 kg (6,845 lb)
Dry mass	1,841 kg (4,059 lb)
Dimensions	26.2 m × 7.5 m (86 ft × 25 ft) withsolar panelsand antennas deployed
Power	5kW
Start of mission
Launch date	17 February 1997, 01:42:02UTC
Rocket	Atlas IIAS
Launch site	Cape Canaveral,LC-36B
Contractor	International Launch Services(ILS)
Orbital parameters
Reference system	Geocentric orbit
Regime	Geostationary orbit
Longitude	124° East
Transponders
Band	Ku-band: 12 × 36Mhz+ 16 × 27 MHz C-band: 12 x 36 MHz
Bandwidth	1296 MHz
Coverage area	Japan,East Asia,South Asia,Australia, New Zealand,Hawaii
TWTA power	Ku-band: 4 × 36 MHz 95 watts 8 × 36 MHz 63 watts 16 × 27 MHz 63 watts C-band: 12 x 36 MHz 34 watts
JCSAT constellation

JCSAT-4was known asJCSAT-Runtil it was sold toIntelsatin 2009 (Intelsat 26). It is ageostationarycommunications satellitedesigned and manufactured byHughes(nowBoeing) on theHS-601satellite bus.It was originally ordered byJSAT Corporation,which later merged into theSKY Perfect JSAT Group.It has a mixedKu-bandandC-bandpayload and was used as an on orbit spare.

Satellite description

The spacecraft was designed and manufactured byHugheson theHS-601satellite bus.It had a launch mass of 3,105 kg (6,845 lb), a dry mass of 1,841 kg (4,059 lb) and a 12-year design life. When stowed for launch, its dimensions were 2.8 m × 4.9 m × 3.8 m (9 ft 2 in × 16 ft 1 in × 12 ft 6 in). With its solar panels fully extended it spanned 26.2 m (86 ft), and its width when its antennas were fully deployed was 7.5 m (25 ft).Its power system generated approximately 5kWof power due to two wings with foursolar panelseach.It also had a singleNiH₂batterycomposed of 30cellsand a 200Ahcharge.It would serve as on orbit backup for theJSAT fleet.

Its propulsion system was composed of anR-4D-11-300liquid apogee engine(LAE) with a thrust of 490 N (110 lb_f). It also used had 12 22 N (4.9 lb_f)bipropellantthrustersforstation keepingandattitude control.It included enough propellant fororbit circularizationand 12 years of operation.Its payload is composed of four octagonal antenna fed by twelve 36MHzand sixteen 27 MHz Ku-band plus twelve 27 MHz C-bandtranspondersfor a total bandwidth of 1296 MHz.Eight of the 36 MHz and the sixteen 27 MHz Ku-band transponders have aTWTAoutput power of 63 watts, the other four 36 MHz ones have 95 watts. It can configure four 27 MHz transponders into a single 54 MHz with an effective 125 watts.The twelve C-band transponders have 36 MHz bandwidth and 34 watts of power.

History

In December 1995,JSATordered its fourth satellite fromHughes,and second of theHS-601platform, theJCSAT-4.It was an almost copy of theJCSAT-3,also based on the HS-601, but with more powerful transponders. It would have a mixed Ku-band and C-band payload, a power generation capability of 5000 watts and a 12 year of design life. It was expected to be delivered by early 1997 and be positioned at the 124° Eastlongitude.It would provide telecommunications and television services to Japan, all ofAsia,Hawaiiand Australia and New Zealand.

On 25 March 1996,International Launch Services(ILS) announced a contract with JSAT for the launch of JCSAT-4 aboard an Atlas IIAS. At the time it was expected to launch in January 1997 from Cape Canaveral at LC-36A launch pad. This was the second contract of ILS with JSAT after the successful launch ofJCSAT-3in August 1995.

On 18 February 1997 at 01:42:02UTC,andAtlas IIASlaunched from Cape CanaveralLC-36Bwith JCSAT-4 towards ageosynchronous transfer orbit(GTO).After the successful launch, it was renamedJCSAT-R.During its tenure as JCSAT-R it operated on the 124° Eastlongitude.In August, 2008, JSAT was merged into theSKY Perfect JSAT Group.

Intelsat 26

In late 2009,Intelsatbought JCSAT-R and rechristened itIntelsat 26.In March 2010, Intelsat announced an agreement withTürksatfor loaning Intelsat 26 so the latter could keep its orbital rights until a new satellite could be launched.In July 2010, it was positioned at the 50° East longitude with a 3.4°inclination.In January 2013, the inclination had increased to 4.6°.In August 2016, the satellite was positioned at 64.1° East with a 6.97° inclination.