In a major step toward strengthening India’s heavy-lift launch capabilities, the Indian Space Research Organisation (ISRO) has successfully conducted the third hot test of its semi-cryogenic engine Power Head Test Article (PHTA) on 28 May 2025 at the ISRO Propulsion Complex in Mahendragiri.
The test is part of an ongoing validation campaign for subsystems that will power the SC120 propulsion stage, slated to replace the current L110 liquid core stage of the LVM3 launch vehicle. The upgrade is expected to significantly enhance the payload capacity of India’s most powerful rocket.
The PHTA, which includes all engine components except the thrust chamber, was tested at 60% of its rated power level, demonstrating stable ignition and controlled performance, ISRO confirmed in an official release. The test article consists of key systems such as the propellant feed system, low- and high-pressure turbo-pumps, pre-burner, start-up mechanism, and associated control components.
This latest 3-second test follows two earlier hot tests:
The first test, conducted on 28 March, confirmed successful ignition and bootstrap operation over 2.5 seconds.
The second, on 24 April, lasted 3.5 seconds and assessed the start-up sequence and transient performance.
The semi-cryogenic engine under development is the SE2000, a 2000 kN-class engine that utilizes liquid oxygen (LOX) as a cryogenic oxidiser and RP-1 (refined kerosene) as a room-temperature hydrocarbon fuel. This combination offers higher thrust, lower cost, and operational simplicity compared to fully cryogenic systems.
Once integrated into the LVM3, the SC120 stage will mark a significant technological leap for ISRO, enabling the agency to undertake more ambitious missions with heavier payloads.
The successful progression of these tests underscores ISRO’s determination to expand its capabilities in global space launch services and support India’s growing ambitions in space exploration and satellite deployment.