GSAT-18
| Company type | Communications satellite |
|---|---|
| Industry | Satellite communications |
| Founded | October 5, 2016 |
| Founder | ISRO |
| Headquarters | India |
| Products | Communications satellite services |
GSAT-18 is a communications satellite from India, developed by ISRO and managed under the INSAT system. It is equipped with 24 C-band, 12 extended C-band, and 12 Ku-band transponders. As of 2025, six of these transponders remain unused, their frequencies currently allocated to GSAT-14, with plans for activation anticipated in early 2027.
The satellite was launched on 5 October 2016 around 20:30 UTC via an Ariane 5 ECA launch vehicle from the Guiana Space Centre. It was placed into a geosynchronous transfer orbit and now occupies the geostationary position at 74° East longitude. The combined expenditure for GSAT-18 and its launch was approximately .
Initially, the launch was set for 12 July 2016 together with Japan's Superbird-8 satellite; however, this was postponed due to damage that Superbird-8 suffered during transit. Following this, Arianespace rescheduled GSAT-18’s launch alongside Australia's Sky Muster II for 4 October 2016, but this was delayed by one day because of strong crosswinds at the launch site.
Orbit raising and station keeping
The satellite’s transfer to its designated geostationary orbit utilized an on-board LAM complemented by chemical thrusters.
| Operation # | Date/ Time (UTC) |
LAM burn duration | Altitude reached | Inclination angle |
Orbital period | |
|---|---|---|---|---|---|---|
| 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 |
| 2 | 8 October 2016 05:59 |
- | 35,840 km (22,270 mi) | 32,518 km (20,206 mi) | 0.129° | 22 hrs, 34 mins |
| 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 |