ISRO Achieves Major Breakthrough in Semicryogenic Engine Development

ISRO has made a significant leap in its Semicryogenic engine development, successfully conducting the first hot test of the Engine Power Head Test Article (PHTA) on March 28, 2025, at the ISRO Propulsion Complex in Mahendragiri, Tamil Nadu.

This 2,000 kN thrust engine, powered by Liquid Oxygen and Kerosene, is set to replace the L110 core liquid stage of the Launch Vehicle Mark-3 (LVM3), enhancing its payload capacity from 4 tonnes to 5 tonnes in Geosynchronous Transfer Orbit (GTO).

The SE2000 engine operates on an oxidizer-rich staged combustion cycle, with a high chamber pressu7re of 180 bar and a specific impulse of 335 seconds. This breakthrough positions India among the few nations mastering high-thrust semicryogenic propulsion technology.

The realization of a test facility to qualify the engine and stage is equally complex and challenging. The complex Semicryogenic Integrated Engine Test facility (SIET) was established at ISRO Propulsion Research Complex (IPRC), Mahendragiri for testing the engine and stage and was dedicated to the nation by the Honourable Prime Minister, Shri Narendra Modi, on February 27, 2024. This facility caters to storage and servicing of large volume of propellants and service fluids at high pressures.

PHTA Hot Test

PHTA Hot Test

The capability of the test stand is validated through several flow and ignition trials. The test stand which involves many sophisticated control components are managed from a Test Control Centre that is also developed indigenously. This facility with a state-of-art PLC-based control system and data acquisition system is capable of testing semi-cryogenic engines up to 2600 kN thrust.

Its a major milestone in India's technological advancements, this milestone aligns perfectly with ISRO's push for indigenous space capabilities.

With this breakthrough, ISRO is further planning a series of tests on the PHTA to further validate and finetune the performance before the realization of the fully integrated engine.

How will this engine improve future ISRO missions?

Power Head Test Article (PHTA)

The SE2000 semicryogenic engine will significantly enhance ISRO's future missions by improving payload capacity, efficiency, and cost-effectiveness. Here’s how:

• Increased Payload Capacity: By replacing the L110 core liquid stage of the LVM3 rocket, the SE2000 engine will boost payload capacity from 4 tonnes to 5 tonnes in Geosynchronous Transfer Orbit (GTO).
• Higher Efficiency: The oxidizer-rich staged combustion cycle allows for higher thrust (2,000 kN) and specific impulse (335 seconds), making launches more efficient.
• Cost Reduction: Using Liquid Oxygen (LOX) and Kerosene as propellants is cheaper and more environmentally friendly compared to traditional cryogenic fuels.

SE2000 Engine

The engine will power next-generation launch vehicles, enabling larger satellites and interplanetary missions.

This breakthrough aligns with ISRO’s push for indigenous space capabilities, strengthening India’s position in global space exploration