GSLV-D5 is the eighth flight of India’s Geosynchronous Satellite Launch Vehicle (GSLV). It is also the fourth developmental flight of GSLV. GSLV-D5 vehicle is configured with its first and second stages similar to the ones flown during earlier GSLV missions. The third stage is the Indigenous Cryogenic Stage. The metallic payload fairing with a diameter of 3.4 metre is adopted for GSLV-D5. S-band telemetry and C-band transponders enable GSLV-D5 performance monitoring, tracking, range safety / flight safety and Preliminary Orbit Determination (POD). GSLV-D5 was launched from the Second Launch Pad (SLP) at Satish Dhawan Space Centre SHAR, Sriharikota on January 05, 2014.
The successful demonstration of the use of cryogenic engine technology in the upper stage of the GSLV puts India among a league five other nations — the US, Russia, France, Japan and China — that possess the technology that is considered the ultimate frontier in rocket science.
The cryogenic stage on the GSLV is the third stage and uses liquid hydrogen as fuel and liquid oxygen as an oxidiser. Cryogenic stage is a highly efficient rocket stage that provides more thrust for every kg of propellant it burns compared to solid and earth-storable liquid propellant stages. The specific impulse achievable with cryo fluids is 450 seconds compared to 300 seconds for other fuels.
Following the successful flight of the GSLV-D5, ISRO is set to attempt flights to launch the GSAT-6, originally intended for the controversial private company Devas Multimedia but subsequently diverted for national security purposes, before opening it for commercial purposes.