❖ ISRO successfully conducted hot testing of liquid rocket engine manufactured through 3D printing technology. 

❖ The engine used is the PS4 engine of PSLV upper stage.

❖ The same engine is also used in the Reaction Control System (RCS) of the first stage (PS1) of PSLV.

❖ The engine uses the earth-storable bipropellant combinations of Nitrogen Tetroxide as oxidizer and Mono Methyl Hydrazine as fuel.