SRIHARIKOTA: Giving a major fillip to the Indian Air Force, the national space agency on Wednesday successfully put into orbit its latest and dedicated military communication satellite ‘GSAT-7A’ that is expected to go a long way in building a centralised network integrating all IAF assets.
Although the Indian Space Research Organisation (ISRO) is tight-lipped on the satellite’s strategic importance, sources say the 2,250 kg tonne GSAT-7A has been customised specifically for military operations.
Congratulating ISRO through an Facebook post for the successful launch of the geostationary satellite, the IAF said, “The GSAT-7A will interlink all the ground-based radars, airbases and AEW&C aircraft for surveillance and to maintain air superiority, it will also enhance KU band communication system.”
ISRO has used an improved version of GSLV MkII for the mission to achieve Super Synchronous Transfer Orbit. Chairman K Sivan told the Express that the cryogenic stage of the rocket was burnt to depletion to achieve an apogee of 39,127 km.
“The cryogenic stage of this vehicle has been modified to increase the thrust rate. The rocket has placed the satellite 2,000 km above what we intended, which means less fuel will be used to carry out orbit raising maneuvers, thereby enhancing the life of the spacecraft.”
Without denying the spacecraft’s defence portfolio, Sivan said GSAT-7A was an advanced communication satellite.
“I am not authorised to comment any further,” he said. However, he said many advancements have been incorporated into the satellite. “For the first time, an off set Gregorian Antenna has been used, which will enhance the performance like providing uninterrupted communication even during heavy weather. We have signed off the year 2018, on a high and positive note,” Sivan added.
The Indian Navy already has a satellite dedicated for its own use, GSAT-7, also called Rukmini, which was launched in 2013. GSAT-7 provides the navy, real-time secure communications capability over the Indian Ocean. GSAT-7A, which suffered multiple delays, will primarily cater to the need of IAF.
Besides these two exclusive military satellites, India has a host of remote sensing or earth observation satellites like CartoSAT series, RadarSAT and a Hyperspectral Imaging Satellite, that provide inputs to secure India’s borders. DK Das, director, Satellite Applications Centre (SAC), said the mission has given a very sophisticated platform for Ku-band communication.
“The satellite has an steerable antenna for regional coverage and an offset Gregorian antenna with 10 transponders for the Indian region. We can fetch two types of services,” he said, without elaborating further.
Earlier in the day, GSLV-F11 lifted-off from the second launch pad at Satish Dhawan Space Centre, Sriharikota. Scientists overcame the threat from Cyclone Phethai to meet the time schedule.
GSLV emerges new workhorse
With the sixth consecutive successful launch, GSLV is becoming India’s next workhorse on par with PSLV and undergoing further advancements to increase the payload carrying capacity.S Somanath, director, Vikram Sarabhai Space Centre, said GSLV MkII is capable of carrying 2-tonne class satellite.
“For this mission, certain improvements in second and cryo stages have been made to accommodate more propellant loading. Cryogenic stage propellant loading has been increased from 12 tonne to 15 tonne. In upcoming GSLV-F12 and GSLV-F13, more wider compartments are planned to fit in heavier spacecrafts. The rocket used in this vehicle is taller by 1.5 meter compared to the previous GSLV MkII launch,” he said, and added that this puts GSLV on the same peddle alongside PSLV, that is known for its reliability and robustness.
This is the seventh and last launch in 2018
GSLV-F11 is the 7th flight of GSLV MkII
The satellite GSAT-7A is the 35th Indian communication satellite. It weights 2,250 kg
The satellite is built to provide communication capability to users in the Ku-band over the Indian region
Customised for military operations, GSAT-7A will improve real-time aircraft-to-aircraft communication
The rocket is equipped with the indigenously developed Cryogenic Upper Stage
This three-stage launch vehicle is 51 meters tall and has a lift-off mass of about 421 tonnes
GSLV-F11 incorporates some major improvements. While the High Thrust Vikas Engine in the second stage enhances the vehicle performance, induction of electro-mechanical actuation system leads to improved reliability
GSAT-7A is the heaviest satellite being launched by GSLV with an indigenously developed cryogenic stage
Chandrayaan-2 on track
Sivan claimed the Chandrayaan-2 project was on track and the space agency was planning to carry out 32 missions next year. “It will be a busy 2019 year for us. Chandrayaan-2 launch is being planned in the first quarter of 2019. The launch window is between January 3 to February end. We are striving hard for that,” he said. ISRO has managed to accomplish 17 missions this year and the next target is raised to 32 missions.