Semi-Cryogenic engine

Semi-Cryogenic engine
 

News: ISRO has successfully begun testing of its semi-cryogenic engine that will power future launch vehicles.
 

What is a semi-cryogenic engine?
 Semi-cryogenic engines are a type of rocket engine that use a combination of liquid and gaseous propellants. They are called “semi-cryogenic” because they operate at temperatures higher than cryogenic engines but still colder than traditional liquid rocket engines.
 The Semi Cryogenic Propulsion System Project envisages the design and development of a 2000 kN semicryogenic engine and ‘SC120 stage’ that will enable the development of a heavy-lift capability for future Indian space transportation systems.
 

Why is ISRO focusing on Semi-Cryogenic engine?
 The semi-cryogenic engine is an advancement in rocket technology over the cryogenic engine, which ISRO currently uses for the Geosynchronous Satellite Launch Vehicle (GSLV) which can carry up to 4 tonnes of payload into higher earth orbit.
 For increased payload, a cryogenic engine would not be enough and hence the development of semicryogenic engines is a key stage in India’s space programme.
 A semi-cryogenic engine uses refined kerosene instead of liquid hydrogen. It uses liquid oxygen as an oxidiser.
 Kerosene is much lighter than liquid fuel and can be stored at a normal temperature. The Kerosene combined with liquid oxygen provides more thrust to the rocket. Compressed Natural Gas (CNG) can also be used as fuel.
 It also occupies less space which makes it possible to have more propellant in the fuel compartment or tank.
 It is environment-friendly, cost-effective and more powerful compared to a cryogenic engine.
Source – PIB, Indian Express