Context: Indian Space Research Organisation (ISRO) successfully launched the INSAT-3DS meteorological satellite onboard a GSLV-F14 from Satish Dhawan Space Centre in Sriharikota.
- The new-generation meteorological satellite is meant to carry out enhanced monitoring of the Earth’s surface, atmosphere, oceans and environment.
- INSAT-3DS will augment the capabilities of the existing two meteorological satellites, INSAT-3D and INSAT-3DR, and boost India’s weather and climate prediction services, early warnings, and disaster management services.
Geosynchronous Satellite Launch Vehicle (GSLV):
- GSLV is one of the three main rockets used by ISRO for carrying its satellites, the other two being PSLV and LVM3 (earlier called GSLV-MkIII).
- Stages: Three-stage launch vehicle.
- First Stage: Uses four strap-on solid boost motors (HS200) each carrying 127 tonnes of propellant. Provides the initial powerful thrust.
- Second Stage: Liquid core stage (L110) powered by two Vikas liquid engines using hypergolic propellants (NTO/UDMH).
- Third Stage: Cryogenic Upper Stage (CUS) with cryogenic engine using liquid hydrogen and liquid oxygen for high specific impulse and efficiency.
- Specialises in placing heavier satellites (2,200 kg and above) into Geosynchronous Orbits (GEO), where they appear stationary relative to Earth. Ideal for large communication satellites.
- GSLV is a more powerful rocket than PSLV and can carry much heavier satellites.
- GSLV can carry more than 2,200 kg to geostationary orbits, and over 6,000 kg to low earth orbits.
Why ‘naughty boy'?
- GSLV has had a rather patchy track record thus far, because of which it has been described as the ‘naughty boy’.
- GSLV had flown 15 times before this, and four of these had been unsuccessful, a very high failure rate for any rocket.
- PSLV, the rocket that ISRO has used the maximum number of times, has failed only twice in its 60 launches, including the first time it was tried way back in 1993.
- LVM3 rocket has flown seven times and never failed.
What is the problem?
- Its problems have mainly been with the cryogenic engine that powers the third and final stage of the flight.
- Cryogenic engines use liquid hydrogen as the main fuel.
- Hydrogen, the most efficient rocket fuel, is very difficult to handle in its natural gaseous form, but manageable in liquid state. However, it liquifies only at very low temperatures, nearly 250 degrees Celsius below zero.
- Oxygen that is needed to burn this fuel also needs to be in liquid form. Oxygen is in a liquid state at about 90 degrees Celsius below zero.
- Cryogenic engines use liquid hydrogen as the main fuel.
- The GSLV uses a cryogenic engine that is reverse-engineered on a Russian design.
- The Russians had won a deal to supply cryogenic engines, and technology, to ISRO in the late 1980s, but that deal had come under pressure from the United States which claimed that it violated provisions of Missile Technology Control Regime, an international legal framework meant to stop the proliferation of missile technology.
- The deal had to be thus called off. Russia did supply a few of those cryogenic engines but could not transfer the technology. India used those engines in some of its launches in the 2000s, and for later flights, tried to reverse-engineer that engine on its own. It is this reverse-engineered engine, used in the GSLV rockets, that has caused a few headaches for ISRO.
Indigenous cryogenic technology in India:
- India has managed to develop its own cryogenic engine as well, a result of decades of research and development. This engine has an entirely Indian design, developed within ISRO, and uses a different process to burn the fuel.
- This indigenously developed cryogenic engine is deployed in LVM3, ISRO’s most powerful rocket so far, which carried the Chandrayaan-2 and Chandrayaan-3 missions, among others. LVM3 has had seven flights till now, without any trouble.