Context:
The Indian Space Research Organisation (ISRO) successfully carried out a short-duration hot test of its semicryogenic engine at the ISRO Propulsion Complex (IPRC) in Mahendragiri. This significant milestone follows the first successful hot test conducted on March 28, marking a major advancement in ISRO’s semicryogenic engine program.
Test Details:
- Test Duration: 3.5 seconds
- Test Focus: Engine Power Head Test Article (excluding thrust chamber)
- Key Outcomes:
- Engine ignited and operated at 60% of its rated power.
- Stable and controlled performance during the test.
- Validation of engine start-up sequence.
Semi-cryogenic Engine
A semi-cryogenic engine is a liquid rocket engine that uses liquid oxygen (LOX) as an oxidizer and refined kerosene as fuel. Unlike fully cryogenic engines which use liquid hydrogen and liquid oxygen, semi-cryogenic engines offer advantages in terms of storage, handling, and cost-effectiveness due to the use of kerosene, which is lighter, more easily storable, and less expensive than liquid hydrogen.
Purpose and Future Plans
- These tests are part of a series aimed at validating the design integrity and performance of key subsystems, including:
- Low-pressure and high-pressure turbo pumps
- Pre-burner and control systems
- The results are crucial for finalizing the operational sequencing of the full semicryogenic engine.
- Further qualification tests are planned to comprehensively validate the engine system, ultimately preparing it for use in ISRO’s launch vehicles.
NASA-ISRO Synthetic Aperture Radar (NISAR) Satellite Launch Preparations
- Launch Vehicle: GSLV-F16
- Current Status: Launch campaign activities for the NISAR satellite have commenced at the Sriharikota launch site.
- Stage Flag-Off: On March 24, 2025, the Second Stage (GS2) of the GSLV vehicle was flagged off from the IPRC, Mahendragiri, to the launch complex at Sriharikota.
- The event was attended by V. Narayanan, Secretary, Department of Space, and Chairman, ISRO, along with directors from IPRC and Vikram Sarabhai Space Centre (VSSC).
- The GS2 liquid stage is designated for the upcoming GSLV-F16 mission to launch the NISAR satellite.





