ISRO suspends hot test for semi-cryogenic engine midway

The Indian space agency encountered a minor setback in developing a semi-cryogenic engine when it prematurely concluded a hot test.

On July 1, 2023, as reported by the Indian Space Research Organisation (ISRO), the agency conducted the initial hot test of an intermediate version of the semi-cryogenic engine referred to as the Power Head Test Article (PHTA) at the ISRO Propulsion Complex (IPRC) located in Mahendragiri, Tamil Nadu. The test was conducted to develop a 2000 kN (kilo Newton) thrust semi-cryogenic engine that would be used to power the booster stages of future launch vehicles. The test progressed as expected until reaching 1.9 seconds, confirming the ignition and subsequent performance of the PHTA.

However, at the 2.0-second mark, an unforeseen increase in turbine pressure occurred, resulting in a subsequent loss of turbine speed. As a precautionary measure, the test was promptly terminated. The ongoing analysis aims to provide further insights into the situation before proceeding with additional hot tests of longer durations.

ISRO stated that the test’s primary objective was to verify the integrated performance of critical subsystems, including the gas generator, turbo pumps, pre-burner, and control components. This involved conducting a short-duration hot-firing lasting 4.5 seconds. The principal objective was the concentrated ignition and generation of hot gas within the pre-burner chamber, which propels the main turbine to drive the fuel and oxidizer pumps.

The semi-cryogenic engine employs a propellant mixture of Liquid Oxygen (LOX) and Kerosene. The power head test article represents the initial tangible examination of the engine development initiative.

Executed at the exclusive testing facility recently established at the Indian Propulsion Research Centre (IPRC), the test signified a significant milestone in evaluating semi-cryogenic engines and stages.

Initiated by the Indian Space Research Organisation (ISRO) in May 2023, the Power Head Test Article (PHTA) was evaluated at the facility as mentioned above.