Technical Problems of GSLV ,Indigenous Production of Cryogenic Engine

The Government has sorted out the technical problems of Geosynchronous Satellite Launch Vehicle (GSLV) which may carry heavy satellites and put them into orbit. The earlier flights GSLV-F02 on July 10, 2006, GSLV-D3 on April 15, 2010 and GSLV-F06 on December 25, 2010 could not accomplish the mission objectives due to technical problems. In GSLV-F02 flight, the primary cause of mission failure has been the loss of thrust in one of the liquid strap-on motors of the first stage. The anomalous behavior was attributed to the malfunctioning of propellant regulator of the gas generator system in this strap-on motor. The GSLV-D3 flight, with indigenous cryogenic upper stage, failed as the indigenous cryogenic engine after its ignition couldn’t sustain the combustion beyond 1 second, due to the anomalous stoppage of Fuel Booster Turbo Pump. In GSLV-F06 flight, with Russian cryogenic upper stage, the primary cause of the failure was the untimely and inadvertent snapping of a group of ten connectors located at the bottom portion of the Russian Cryogenic Stage, due to structural failure of the Lower Shroud. Based on the suggestions made by the failure analysis committees, ISRO has implemented the modifications and improvements in GSLV, which include independent inspection and quality checks for all critical components and sub-assemblies, change of bearing housing material, revision of tolerances and seal clearances of Fuel Booster Turbo Pump of Cryogenic Engine, redesign of the Cryogenic Stage Lower Shroud, revision of connector mounting scheme and wire tunnel configuration. After implementing the modifications and improvements in GSLV, the next flight GSLV-D5 was successfully launched on 5th January 2014 from Satish Dhawan Space Centre, Sriharikota. India has prepared its own indigenous cryogenic engines meant for GSLV and flown in GSLV-D3 and GSLV-D5. Cryogenic engine required for next flight GSLV-D6 is also prepared and is undergoing acceptance testing. Indigenous Production of Cryogenic Engine The Cryogenic Engine of 7.5 Tonne thrust meant for Geosynchronous Satellite Launch Vehicle (GSLV) is indigenously produced and successfully flight tested in GSLV-D5 flight on 5th January 2014. The Cryogenic Engine of higher thrust (20 Tonne) meant for next generation of GSLV viz. GSLV-MkIII launch vehicle is under advanced stage of development. Design and Development tests of sub-system elements of this new high-thrust cryogenic engine have been carried out successfully. Cryogenic engines are already in production in Indian industries. So far, eleven cryogenic engines for GSLV and two higher thrust cryogenic engines for GSLV Mk-III have been realized. In the twelfth five year plan, 192 Crores has been allocated for realisation of cryogenic engines and stages, under GSLV programme.