ISRO Tests Its Semi-Cryogenic Rocket Engine at Full 200-Tonne Thrust

The Indian Space Research Organisation (ISRO) on Saturday successfully conducted a hot test of its Semi-Cryogenic Engine Power Head Test Article (PHTA) at full thrust of 200 tonnes, at the ISRO Propulsion Research Complex (IPRC) in Mahendragiri, Tamil Nadu. It was the ninth hot test in the series and the first time the PHTA was tested at 100 per cent thrust.

The PHTA includes all of the engine's systems except the thrust chamber. Earlier tests in the series had reached 47 per cent (94 tonnes), 60 per cent (120 tonnes) and 88 per cent (175 tonnes) of full thrust. Saturday's test lasted 35 seconds in total, including five seconds of the engine power head running at the full 200-tonne, 100 per cent thrust level, with all engine parameters behaving as predicted throughout.

The test also validated switching the propellant supply from a low-pressure start tank to a medium-pressure run tank, a step that will allow the PHTA to be tested for longer durations in future hot tests.

The Semi-Cryogenic Propulsion Stage, called SC120 and powered by the 2,000 kN-class SE2000 engine, is being developed to replace the current L110 core stage of ISRO's LVM3 launch vehicle. A semi-cryogenic engine burns refined kerosene with liquid oxygen, a fuel combination that is easier to store and handle than the supercooled liquid hydrogen a fully cryogenic engine uses. Integrating the semi-cryogenic stage with an uprated cryogenic upper stage, called C32, is intended to increase how much payload the LVM3 can carry.