ISRO is considering using kerosene for semi-cryogenic engine

Indian Space Research Organisation (ISRO) is working on developing a semi-cryogenic engine that will run on eco-friendly kerosene oil, which is lighter than liquid fuel and doesn’t need extreme temperature conditions to be stored.

Presently, the fuel being used, which is a combination of liquid hydrogen and liquid oxygen, is heavier and needs to be stored at -253 degree Celsius.

ISRO will reportedly flight-test the semi-cryogenic engine by 2021 if everything goes as planned.

"Kerosene is a fuel lighter than the conventional combination of liquid hydrogen and liquid oxygen but it gives higher thrust. Therefore kerosene occupies less space and more propellant can be packed in the semi-cryogenic engine's fuel compartment. However, liquid oxygen will be retained as oxidiser. The advantage of using this semi-cryogenic engine is the payload capacity of the launch vehicle will increase from four tonnes to six tonnes. This kind of rocket with the semi-cryogenic engine can therefore take heavier satellites into space and can also be used for interplanetary missions and deep space missions," Dr K Sivan, Director of Thiruvananthapuram-based Vikram Sarabhai Space Centre told TOI.

"We will only replace the second stage of the launch vehicle like GSLV Mk-III, which now uses liquid fuel, with the semi-cryogenic engine. The rocket will retain the cryogenic upper third stage," he continued.

"Space agencies of many countries like the US and Russia have been using the semi-cryogenic engine as it gives high thrust. In fact, Falcon-9 of SpaceX (the first US commercial company whose rocket has made multiple flights to the International Space Centre) has also been using the semi-cryogenic engine technology," Dr Sivan added.

The semi-cryogenic engine project was cleared by the Union Cabinet in 2008 at an estimated cost of Rs 1,798 crore. While initially the technology was to be developed in 2014, the project got delayed.