ISRO's Semi Cryogenic Engine test rig at Liquid Propulsion Systems Centre

ISRO Semi Cryogenic Engine at final stage's of development, it is also learnt that SCE will have regenerative cooling systems using its fuel kerosene.

On July 1, 2023, ISRO conducted the first hot test on an intermediate configuration of the Semi-cryogenic Engine, known as Power Head Test Article (PHTA) at ISRO Propulsion Complex (IPRC), Mahendragiri, Tamil Nadu. The test was conducted towards developing a 2000kN thrust semi-cryogenic engine to power the booster stages of future launch vehicles.

The objective of the test was to validate the integrated performance of the critical subsystems such as the gas generator, turbo pumps, pre-burner and control components by carrying out a hot-firing for a short-duration of 4.5 s. The ignition and generation of hot-gas within the pre-burner chamber that drives the main turbine to drive the fuel and oxidiser pumps, was focussed.

The test proceeded as predicted till 1.9 s validating the ignition and subsequent performance of PHTA. At 2.0 s, an unanticipated spike in the turbine pressure and subsequent loss of turbine-speed was observed. As a precautionary step, the test was terminated. Analysis under progress would offer further understanding before proceeding with further hot-tests for longer duration.

The semi-cryogenic engine utilizes a propellant combination of Liquid Oxygen (LOX) and Kerosene, and the power head test article forms the first hardware test of the engine development program. The test was carried out the dedicated test facility recently established at IPRC for testing semi-cryogenic engines and stages. ISRO had commenced the testing of the PHTA in May 2023 at this facility.