India on July 15 successfully launched its latest communication satellite GSAT-12 onboard a powerful variant of homegrown Polar Satellite Launch Vehicle, PSLV-C17, from the spaceport in Sriharikota.
In a textbook launch, Indian Space Research Organisation’s workhorse PSLV lifted off from the second launch pad of the Satish Dhawan Space Centre here at 4.48 pm at the end of the 53-hour countdown and placed the 1,410 kg GSAT-12 into orbit about 20 minutes later.
“I am extremely happy to state that the PSVL-C17 GSAT12 mission is successful. The launch vehicle injected the satellite very precisely into the intended orbit,” a beaming ISRO Chairman K. Radhakrishnan announced.
On its 18th successful mission in a row, the PSLV zoomed into cloudy skies as scientists broke into cheers at the mission control centre here, 90 km from Chennai.
GSAT-12 was injected into an elliptical Transfer Orbit of 284 km perigee (closest point to Earth) and 21,000 km apogee (farthest point to Earth).
Subsequently, the onboard Liquid Apogee Motor would be used to place the satellite in a circular orbit.
GSAT-12, aimed at augmenting the capacity in the INSAT system for various communication services like tele-education, tele-medicine and Village Resource Centres, would be co-located with INSAT-2E and INSAT-4A satellites.
This was the second time in its 19 flights that the PSLV has been used for launching a communication satellite after Kalpana-1 in 2002.
ISRO used the most powerful XL configuration with six extended solid strap-on motors carrying 12 tonnes of solid propellant as against nine tonnes for the standard PSLV for Friday’s flight. A similar configuration was used for launching India’s maiden Chandrayaan-1 lunar mission in 2008.
ISRO chose its reliable launch vehicle PSLV in the face of failures of two previous GSLV flights in April and December 2010 that dealt a blow to the missions to place GSAT-5 and GSAT-5P into orbit causing transponder shortage.
Launch of GSAT-12, equipped with 12 Extended C-band transponders, is expected to partly meet the country’s growing demand for transponders in a short turnaround time.
PSLV-C17:
Polar Satellite Launch Vehicle (PSLV-C17), in its nineteenth flight, launches India's communication satellite GSAT-12 from the Second Launch Pad of Satish Dhawan Space Centre, SHAR, Sriharikota, India. PSLV-C17 measuring 44.5 m height, with a lift off weight of 320 tonnes has four stages of solid and liquid propulsion systems alternately. In its XL Version, PSLV-XL uses six extended solid strap-on motors wherein each strap-on carries 12 tonnes of solid propellant. This is a second time such a configuration is being flown, earlier one being the PSLV-C11/Chandrayaan-I mission.
Salient feature of PSLV-C17/GSAT-12 Mission:
Polar Satellite Launch Vehicle (PSLV-C17), in its nineteenth flight, launches India's communication satellite GSAT-12 from the Second Launch Pad of Satish Dhawan Space Centre, SHAR, Sriharikota, India. PSLV-C17 measuring 44.5 m height, with a lift off weight of 320 tonnes has four stages of solid and liquid propulsion systems alternately. In its XL Version, PSLV-XL uses six extended solid strap-on motors wherein each strap-on carries 12 tonnes of solid propellant. This is a second time such a configuration is being flown, earlier one being the PSLV-C11/Chandrayaan-I mission.
Salient feature of PSLV-C17/GSAT-12 Mission:
- For the first time, use of indigenously designed and developed On-Board computer (OBC) with Vikram 1601 processor in both primary and redundant chains of the vehicle. The OBC performs the functions of Navigation, Guidance and Control processing for the vehicle.
- Use of extended solid strap-on configuration
- Satellite injection in elliptical transfer orbit sub-Geosynchronous Transfer Orbit (GTO)
- Five burn strategy (2 perigee burn and 3 apogee burn) for placing the GSAT-12 satellite from its sub-GTO to Geostationary Orbit
PSLV- C17 Stages at a Glance | ||||
STAGE-1 | STAGE-2 | STAGE-3 | STAGE-4 | |
Nomenclature | Core Stage(PSI) + 6 Strap-on Motors | PS2 | PS3 | PS4 |
| Propellant | Solid (HTPB Based) | Liquid (UH25+N2O4) | Solid (HTPB Based) | Liquid (MMH + MON-3) |
| Mass (Tonne) | 138.0 (Core) + 6 x 12.0 (Strap-on) | 41.0 | 7.6 | 2.5 |
| Max Thrust (kN) | 4703 (Core) 6 x 670(Strap-on) | 804 | 244 | 7.3 x 2 |
| Burn Time (sec) | 107 (Core) 55 (Strap-on) | 151 | 116 | 510 |
| Stage Dia (m) | 2.8 (Core) 1.0 (Strap-on) | 2.8 | 2.0 | 2.8 |
| Stage Length (m) | 20 (Core) 14.7 (Strap-on) | 12.8 | 3.6 | 2.6 |
GSAT-12:
GSAT-12, the latest communication satellite built by ISRO, weighs about 1410 kg at lift-off. GSAT-12 is configured to carry 12 Extended C-band transponders to meet the country's growing demand for transponders in a short turn-around-time. The 12 Extended C-band transponders of GSAT-12 will augment the capacity in the INSAT system for various communication services like Tele-education, Telemedicine and for Village Resource Centres (VRC).
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