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| GSLV Mark-3 (Image credits- Wikimedia Commons/ISRO) |
A little insight into what GSLV Mark-3 is all about and why this launch is so important for India:
The Geosynchronous Satellite Launch Vehicle Mark III is a launch vehicle developed by the Indian Space Research Organisation (ISRO). It is intended to launch satellites into geostationary orbit and as a launcher for an Indian crew vehicle. The GSLV-III features an Indian cryogenic third stage and a higher payload capacity than the current GSLV Mark-1 and 2. Development for the GSLV-III began in the early 2000s, with the first launch planned for 2009-2010.Several factors have delayed the program, including the 15 April 2010 failure of the ISRO-developed cryogenic upper stage on the GSLV Mk II.
A suborbital flight test of the GSLV-III launcher, with a passive cryogenic third stage, was successfully carried out on 18 December 2014, and was used to test a crew module on a suborbital trajectory. The first orbital flight is planned to take place in 2017. The first flight with a crew on board would take place after 2020.
Tests:
The S-200 solid rocket booster was successfully tested on 24 January 2010. The booster fired for 130 seconds and generated a peak thrust of about 500 tonnes. Nearly 600 ballistic and safety parameters were monitored during the test and indicated normal performance. A second successful static test was conducted on 4 September 2011.The Indian Space Research Organisation conducted the first static test of the L110 core stage at its Liquid Propulsion Systems Centre (LPSC) test facility at Mahendragiri, Tamil Nadu on 5 March 2010. Originally targeted for a full 200 second burn, the test was terminated at 150 seconds after a leakage in a control system was detected.On 8 September 2010 ISRO successfully conducted a full 200 second test .
The GSLV LVM-3 lifted off from the second launch pad, Sriharikota, at 9.30 am IST on 18 December 2014. The 630.5 tonne launch vehicle stacking was as follows : a functional S200 solid propulsion stage, a functional L110 liquid propulsion stage, a non-functional dummy stage (in lieu of CE-20 cryogenic propulsion engine) and finally the 3.7-tonne Crew Module Atmospheric Re-entry Experiment (CARE) payload stage. Just over five minutes into the flight, the rocket ejected CARE at an altitude of 126 km. CARE then descended at high speed, controlled by its onboard motors. At an altitude of 80 km, the thrusters were shut down and the capsule began its ballistic re-entry into the atmosphere. CARE’s heat shield was expected to experience a temperature of around 1600 °C. ISRO downloaded launch telemetry during the ballistic coasting phase prior to the radio black-out to avoid data loss in the event of a splash-down failure. At an altitude of around 15 km, the module’s apex cover separated and the parachutes were deployed. CARE splashed down in the Bay of Bengal near the Andaman and Nicobar Islands.The first hot test of the C25 cryogenic stage was conducted at ISRO Propulsion Complex (IPRC) facility at Mahendragiri, Tamil Nadu on 25 January 2017. The stage was hot tested for a duration of 50 seconds demonstrating all stage operations. A longer duration test for 640 seconds was completed on Feb 18 2017.
Vehicle Description:
First Stage: The S200 solid motors are used as the first stage of the launch vehicle. Each booster has a diameter of 3.2 metres, a length of 25 metres, and carries 207 tonnes of propellant. These boosters burn for 130 seconds and produce a peak thrust of about 5,150 kilonewtons (525 tf) each.
A separate facility has been established at Sriharikota to make the S200 boosters. Another major feature is that the S200’s large nozzle has been equipped with a ‘flex seal.’ The nozzle can therefore be gimballed when the rocket’s orientation needs correction. In flight, as the thrust from the S200 boosters begins to tail off, the decline in acceleration is sensed by the rocket’s onboard sensors and the twin Vikas engines on the ‘L110’ liquid propellant core stage are then ignited. Before the S200s separate and fall away from the rocket, the solid boosters as well as the Vikas engines operate together for a short period of time,similar of that American Titan III and Titan IV booster.
Second Stage: The second stage, designated L110, is a 4-meter-diameter liquid-fueled stage carrying 110 tonnes of UDMH and N2O4. It is the first Indian liquid-engine cluster design, and uses two improved Vikas engines, each producing about 700 kilonewtons (70 tf). The improved Vikas engine uses regenerative cooling, providing improved weight and specific impulse, compared to earlier rockets.The L110 core stage ignites 113 seconds after liftoff and burns for about 200 seconds.
Third Stage: The cryogenic upper stage is designated the C25 and will be powered by the Indian-developed CE-20 engine burning LOX and LH2, producing 186 kilonewtons (19.0 tf) of thrust. The C-25 will be 4 metres (13 ft) in diameter and 13.5 metres (44 ft) long, and contain 27 tonnes of propellant.
This engine was initially slated for completion and testing by 2015, it would have been the C25 stage and be put through a series of tests. ISRO crossed a major milestone in the development of CE-20 engine for the GSLV MKIII vehicle by the successful hot test for 640 seconds duration on 19 February 2017 at ISRO Propulsion Complex, Mahendragiri. The test demonstrated the repeat-ability of the engine performance with all its sub systems like thrust chamber, gas generator, turbo pumps and control components for the full duration. All the engine parameters were closely matching with the pre-test prediction.
The first C25 stage will be used on the GSLV-III D-1 mission in late may 2017 launch. This mission will put in orbit the GSAT-19E communication satellite. Work on the C25 stage and CE-20 engine for GSLV Mk-III upper stage was initiated in 2003, the project has been subject to many delays due to problems with ISRO's smaller cryogenic engine, the CE-7.5 for GSLV MK-II upper stage.
The first launch with a non functional cryo upper stage took place on 18.12.2016. This test also carried This test was mainly to test the stability and behavior of the vehicle during launch. The main payload of the test was Crew Module Atmospheric Re-entry Experiment (CARE) which is the model of the future crew module. Both the vehicle and CARE met with the launch parameters. The first launch with a functional cryogenic stage took place on 5.06.2017 which was a complete success and met all the parameters. The launcher put into orbit GSAT-19 which is of 3.5 tonnes and is a high performance satellite.
The importance of GSLV Mark-3 for India:
GSLV Mark-3 has got great importance for India. It will not only reduce the dependence on foreign launchers including Ariane but also allow India to become self sufficient in Satellite launch. GSLV Mark-3 will also be the launcher that will ferry the future Indian astronauts into space. There is also the project to enhance GSLV Mark-3 to carry 6 tonnes of Satellite into space.
I take this opportunity to congratulate ISRO on this remarkable achievement. May they grower to greater heights and may they have all the success.
Vante Mathram
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