were enhanced, enabling a higher propellant mass and burn time. These improvements allowed GSLV to carry an additional 300 kg of payload. The fourth operational flight of GSLV Mark I, GSLV-F06, had a longer third stage called the C15 with 15 tonne propellant loading and also employed a diameter payload fairing. GSLV Mark II This variant uses an Indian cryogenic engine, the CE-7.5, and is capable of launching 2500 kg into geostationary transfer orbit. Previous GSLV vehicles (GSLV Mark I) have used Russian cryogenic engines. For launches from 2018, a 6% increased thrust version of the Vikas engine was developed. It was demonstrated on 29 March 2018 in the GSAT-6A launch second stage. It was used for the four Vikas engines first stage boosters on future missions. A 4m diameter Ogive payload fairing was developed and deployed for the first time in the EOS-03 launch on 12 August 2021, although this launch was a failure due to technical anomalies with the Cryogenic Upper Stage. This will allow GSLV vehicles to accommodate larger payloads. Launch history Launch system status Gallery See also Comparison of orbital launchers families Comparison of orbital launch systems LVM 3 PSLV ISRO ASLV SLV References External links ISRO GSLV Page INDIA in Space – GSLV Page 12KRB (KVD-1) Upper Stage at Khrunichev Space Center ISRO space launch vehicles 2001 in spaceflight Satish Dhawan Space Centre Vehicles introduced in 2001 Expendable space launch systems