GSAT-6A
Indian telecommunications satellite
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GSAT-6A was a communication satellite launched by the Indian Space Research Organisation (ISRO). It featured a 6-metre (20 ft) unfurlable S-band antenna similar to the one used on GSAT-6.[1] Around 17 minutes after lift-off, the three stage GSLV Mk.II rocket flying on GSLV F08 mission successfully injected the satellite into a geosynchronous transfer orbit.[3] Due to power failure during its orbit raising burns the communication was lost with GSAT-6A[4][5] before it could reach its final circular geostationary orbit (GSO).
| |
| Mission type | Communications |
|---|---|
| Operator | ISRO |
| COSPAR ID | 2018-027A |
| SATCAT no. | 43241 |
| Website | www |
| Mission duration | Planned: 10 years |
| Spacecraft properties | |
| Bus | I-2K |
| Manufacturer | ISRO Satellite Centre Space Applications Centre |
| Launch mass | 2,117 kilograms (4,667 lb) |
| Dimensions | 1.53 × 1.65 × 2.4 m (5.0 × 5.4 × 7.9 ft) |
| Power | 3,119 watts |
| Start of mission | |
| Launch date | 29 March 2018, 11:26 UTC[1] |
| Rocket | GSLV Mk.II F08 |
| Launch site | Satish Dhawan SLP |
| Contractor | ISRO |
| Entered service | Failed before being operational |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Geostationary |
| Slot | 83°E (Planned) |
| Semi-major axis | 37,552 kilometers (20,276 nmi)[2] |
| Eccentricity | 0.1383056[2] |
| Perigee altitude | 29,580 kilometers (15,970 nmi)[2] |
| Apogee altitude | 36,367 kilometers (19,637 nmi)[2] |
| Inclination | 3.29 degrees[2] |
| Period | 20.8 hours[2] |
| RAAN | 158.9 degrees[2] |
| Argument of perigee | 184.72 degrees[2] |
| Mean anomaly | 125.81 degrees[2] |
| Mean motion | 1.19302622[2] |
| Epoch | April 11, 2018[2] |
| Revolution no. | 17[2] |
| Transponders | |
| Coverage area | India |
History
Launch
GSLV-F08 carrying GSAT-6A spacecraft was launched from Second Launch Pad of Satish Dhawan Space Centre on 29 March 2018, 11:26 UTC and after flight of 17 minutes 45 seconds,[10] placed GSAT-6A into its planned geostationary transfer orbit with 36,692.5 kilometres (22,799.7 mi) apogee, 169.4 kilometres (105.3 mi) perigee and orbital inclination of 20.64°. GSAT-6A spacecraft deployed its solar array after separation from CUS and established contact with ground station.[11]
On GSLV-F08, a High Thrust Vikas engine (HTVE) was inducted on second stage (GS2) of GSLV with 6% higher thrust than before.[12][13] The improved engine increased the payload capability of the vehicle.[10] The electrohydraulic actuation system on second stage was also replaced with simpler and robust electromechanical system.[13] The Cryogenic Upper Stage of GSLV F08 performed a burn to depletion for the first time. Officials said any improvement done to the vehicle would be incorporated into GSLV's future missions.[10]
Loss of communication
The first orbit raising maneuver for GSAT-6A was carried out as planned on 30 March 2018 by firing the Liquid Apogee Motor (LAM) for 2188 seconds from 09:22 AM IST. The second orbit raising maneuver was carried out at 10:00 AM on 31 March 2018. As the satellite was on-course for its third and final orbit raising maneuver on 1 April 2018, communication with it was lost and the spacecraft was temporarily untraceable.[14][15][5] After regaining its track,[16] efforts to re-establish communication with the satellite could not succeed.[17][18] Power system malfunction was suspected to be the reason behind loss of contact.[19][20][21]
Satellite replacement
ISRO will launch GSAT-32 satellite as replacement for GSAT-6A.[22]
