First hot test of Semi-cryogenic engine terminated midway due to Spike in turbine pressure: ISRO

Bengaluru, July 3. The Indian Space Research Organisation (ISRO) Chairman S. Somanath confirmed to India Strategic, that the Space Agency has terminated midway, the first hot test of a semi-cryogenic engine due to unanticipated spike in turbine pressure and loss of turbine speed.

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 the ISRO Propulsion Complex (IPRC), Mahendragiri in Tamil Nadu.

The Space agency said the test was conducted towards developing a 2000 kN 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 secs.

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 seconds validating the ignition and subsequent performance of PHTA.

“At 2.0 seconds, an unanticipated spike in the turbine pressure and subsequent loss of turbine-speed was observed, ISRO said.

As a precautionary step, the test was terminated”, it said. 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 at the dedicated test facility recently established at the IPRC for testing semi-cryogenic engines and stages.

ISRO had commenced the testing of the PHTA in May 2023 at this facility.