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.
 | |
| Mission type | Communications |
|---|---|
| Operator | INSAT |
| COSPAR ID | 2016-060A |
| SATCAT no. | 41793 |
| Website | GSAT-18 |
| Mission duration | Planned: 15 years Elapsed: 8 years, 1 month, 6 days |
| Spacecraft properties | |
| Bus | I-3K[1] |
| Manufacturer | ISRO Satellite Centre Space Applications Centre |
| Launch mass | 3,404 kg (7,505 lb)[2] |
| Dry mass | 1,480 kg (3,263 lb)[2] |
| Power | 6,474 watts[2] |
| Start of mission | |
| Launch date | 5 October 2016, ≈20:30 UTC[3] |
| Rocket | Ariane 5 ECA, VA-231[1] |
| Launch site | Guiana Space Centre ELA-3[1] |
| Contractor | Arianespace[1] |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Geostationary |
| Longitude | 74° E |
| Perigee altitude | 35,750 km (22,214 mi) |
| Apogee altitude | 35,822 km (22,259 mi) |
| Inclination | 0.0616° |
| Epoch | 11 June 2017 01:46:00 UTC[4] |
| Transponders | |
| Band | 24 × C band 12 × extended C band 12 × Ku band 2 × Ku beacon |
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 keeping
editOrbit 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] |
References
edit
- ^ 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.
- ^ a b c d "GSAT-18" (PDF). Indian Space Research Organisation. Archived from the original (PDF) on 2016-12-13. Retrieved 2017-06-12.
- ^ a b Bergin, Chris (5 October 2016). "Ariane 5 launches Sky Muster II and GSAT-18". NASA Spaceflight. Retrieved 6 October 2016.
- ^ "GSAT-18 - Orbit". Heavens-Above. 11 June 2017. Retrieved 12 June 2017.
- ^ "India's communication satellite GSAT-18 launched successfully". Business Standard. Press Trust of India. 6 October 2016. Retrieved 6 October 2016.
- ^ "Launch Schedule". Spaceflight Now. 4 October 2016. Archived from the original on 5 October 2016.
- ^ Clark, Stephen (5 October 2016). "Ariane 5 goes on test run after launching two satellites". Spaceflight Now. Retrieved 6 October 2016.
- ^ 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.
- ^ D. S., Madhumathi (10 July 2016). "Deferred GSAT-18 awaits October launch at Kourou". The Hindu. Retrieved 10 September 2016.
- ^ "Sky Muster II comes to French Guiana for launch on Ariane 5". Arianespace. 31 August 2016. Retrieved 10 September 2016.
- ^ "Bad weather delays Isro's launch of communications satellite GSAT-18". Hindustan Times. Press Trust of India. 5 October 2016. Retrieved 5 October 2016.
- ^ "The first orbit raising manoeuvre..." Indian Space Research Organisation. 7 October 2016. Retrieved 12 June 2017.
- ^ "The second orbit raising manoeuvre..." Indian Space Research Organisation. 8 October 2016. Retrieved 12 June 2017.
- ^ "Third LAM firing of GSAT-18..." Indian Space Research Organisation. 9 October 2016. Retrieved 12 June 2017.
- ^ "Orbit Determination results..." Indian Space Research Organisation. 9 October 2016. Retrieved 12 June 2017.