Successful Boot-Strap Mode Start Test on CE20 Cryogenic Engine
The Indian Space Research Organisation (ISRO) has successfully conducted a boot-strap mode start test on the CE20 Cryogenic engine, which is pivotal for the upper stage of the Launch Vehicle Mark-3 (LVM3) rocket. This test, performed under vacuum conditions at the High-Altitude Test (HAT) facility in ISRO Propulsion Complex, Mahendragiri, marks a significant development in enhancing the engine's capabilities.
Key Achievements and Details
- The test was executed on November 7, 2025, for a duration of 10 seconds.
- The CE20 engine is already certified for thrust levels between 19 to 22 tonnes with a single start.
- This engine is also utilized for the Gaganyaan missions.
Current Operation and Challenges
The standard operation involves ignition initiated under tank head conditions, followed by turbo pumps activated through a stored gas start-up system. The current configuration requires additional equipment for each restart, impacting payload capacity.
Future Mission Requirements
- Future missions will necessitate multiple in-flight restarts for mission flexibility in multi-orbit undertakings.
- To address this, the boot-strap mode start is crucial as it allows the engine to reach steady operation without external start-up assistance.
Test Methodology and Outcome
- A multi-element igniter was used in the thrust chamber and gas generator during the test.
- After thrust chamber ignition, the gas generator was ignited under tank head conditions.
- Turbo pumps were started without a start-up system, successfully demonstrating the boot-strap mode build-up and steady operation.
Significance
This achievement represents a unique global milestone where ISRO demonstrated boot-strap mode starting of a gas-generator cycle cryogenic engine without any auxiliary start-up system.
