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GSAT-18 is an Indian communications satellite. Built by ISRO and operated by INSAT, it carries 24 C-band, 12 extended C-band, and 12 Ku-band transponders.

GSAT-18
GSAT-18.png
Mission typeCommunications
OperatorINSAT
COSPAR ID2016-060A
SATCAT no.41793
WebsiteGSAT-18
Mission durationPlanned: 15 years
Elapsed: 3 years, 2 days
Spacecraft properties
BusI-3K[1]
ManufacturerISRO Satellite Centre
Space Applications Centre
Launch mass3,404 kg (7,505 lb)[2]
Dry mass1,480 kg (3,263 lb)[2]
Power6,474 watts[2]
Start of mission
Launch date5 October 2016 (2016-10-05), ≈20:30 UTC[3]
RocketAriane 5 ECA, VA-231[1]
Launch siteGuiana Space Centre ELA-3[1]
ContractorArianespace[1]
Orbital parameters
Reference systemGeocentric
RegimeGeostationary
Longitude74° E
Perigee altitude35,750 km (22,214 mi)
Apogee altitude35,822 km (22,259 mi)
Inclination0.0616°
Epoch11 June 2017 01:46:00 UTC[4]
Transponders
Band24 × C band
12 × extended C band
12 × Ku band
2 × Ku beacon
← GSAT-15
GSAT-9 →
 

The satellite was launched on 5 October 2016 at approximately 20:30 UTC aboard an Ariane 5 ECA rocket from the Guiana Space Centre in Kourou, French Guiana.[3][5] The launch vehicle inserted the satellite into a geosynchronous transfer orbit, and once in service it will occupy the orbital slot at 74° East longitude.[1][6] The total cost of the satellite and launch services was about US$153 million.[7]

GSAT-18 was originally scheduled to launch on 12 July 2016 alongside Japan's Superbird-8 satellite, but a shipping mishap which damaged Superbird-8 forced a delay in the launch schedule.[8][9] Arianespace later paired GSAT-18 with Australia's Sky Muster II for a 4 October 2016 launch.[10] The launch was delayed 24 hours to 5 October due to excessively high crosswinds at the launch site.[11]

Orbit raising and station keepingEdit

Orbit raising operations were made using an on-board LAM and chemical thrusters[2] to place the satellite in the intended geostationary orbital slot.

Op # Date/
Time (UTC)
LAM burn time Height achieved Inclination
achieved
Orbital period References
Apogee Perigee
1 6 October 2016
10:16
6040.6 sec 35,802 km (22,246 mi) 14,843 km (9,223 mi) 1.325° 15 hrs, 36 mins [12]
2 8 October 2016
05:59
- 35,840 km (22,270 mi) 32,518 km (20,206 mi) 0.129° 22 hrs, 34 mins [13]
3 9 October 2016
04:51
256.17 sec 35,802 km (22,246 mi) 35,294 km (21,931 mi) 0.136° 23 hrs, 44 mins [14][15]

ReferencesEdit

  1. ^ a b c d e "Annual Report 2015-2016" (PDF). Indian Space Research Organisation. December 2015. p. 28. Archived from the original (PDF) on 2016-07-05.
  2. ^ a b c d "GSAT-18" (PDF). Indian Space Research Organisation.
  3. ^ a b Bergin, Chris (5 October 2016). "Ariane 5 launches Sky Muster II and GSAT-18". NASA Spaceflight. Retrieved 6 October 2016.
  4. ^ "GSAT-18 - Orbit". Heavens-Above. 11 June 2017. Retrieved 12 June 2017.
  5. ^ "India's communication satellite GSAT-18 launched successfully". Business Standard. Press Trust of India. 6 October 2016. Retrieved 6 October 2016.
  6. ^ "Launch Schedule". Spaceflight Now. 4 October 2016. Archived from the original on 5 October 2016.
  7. ^ Clark, Stephen (5 October 2016). "Ariane 5 goes on test run after launching two satellites". Spaceflight Now. Retrieved 6 October 2016.
  8. ^ de Selding, Peter B. (20 June 2016). "Japan's DSN-1 military communications satellite damaged during transport to launch base". Space News. Retrieved 10 September 2016.
  9. ^ D. S., Madhumathi (10 July 2016). "Deferred GSAT-18 awaits October launch at Kourou". The Hindu. Retrieved 10 September 2016.
  10. ^ "Sky Muster II comes to French Guiana for launch on Ariane 5". Arianespace. 31 August 2016. Retrieved 10 September 2016.
  11. ^ "Bad weather delays Isro's launch of communications satellite GSAT-18". Hindustan Times. Press Trust of India. 5 October 2016. Retrieved 5 October 2016.
  12. ^ "The first orbit raising manoeuvre..." Indian Space Research Organisation. 7 October 2016. Retrieved 12 June 2017.
  13. ^ "The second orbit raising manoeuvre..." Indian Space Research Organisation. 8 October 2016. Retrieved 12 June 2017.
  14. ^ "Third LAM firing of GSAT-18..." Indian Space Research Organisation. 9 October 2016. Retrieved 12 June 2017.
  15. ^ "Orbit Determination results..." Indian Space Research Organisation. 9 October 2016. Retrieved 12 June 2017.