The cryogenic engine is crucial to the development of GSLV.
The term cryogenic refer to technology of sub-zero temperatures and cryogenic engine uses liquid hydrogen as a fuel and liquid oxygen as oxidizers. As both the fuel and the oxidizer are gaser at ordinary temperatures and their liquefaction requires use of the techniques and systems at sub-zero temperatures.
The use of liquefied fuel instead of solid fuels or earth-stroke liquid fuels like kerosene helps the engine to produce greater thrust for the same quantity of propellant. Due to this, cryogenic engine is able to place a far heavier load. The American Atlas- centaur rocket was the first to use cryogenic rocket technology.
The cryogenic technology is also very complicated one because the use of special insulation and materials that can withstand temperatures of minus 200 degrees or less (as foiling point of liquid hydrogen is -253°c) In India, the cryonic engine is crucial to the development of Geo-synchronous Satellite Launch
Vehicle (GSLV). Due to the advantage of cryogenic engine, GSLV is capable of injecting more than 2500 kg class communication satellites into the geosynchronous circular orbits at an attitude of 3600 km. it is high risk high technology and would help bridge the gap between the number of satellites being made by India and the vehicles needed for their launch. The realization of the cryogenic technology would also help India to become a partner is space explorations and activities of other countries.