ISRO Conducts Sea-Level Hot Test of CE20 Cryogenic Engine

On 12th March 2026, the Indian Space Research Organisation (ISRO) successfully conducted a sea-level hot test of the CE20 cryogenic engine at 22-tonne thrust at the ISRO Propulsion Complex in Mahendragiri, Tamil Nadu.

Key Points

CE20 Cryogenic Engine: The CE20 engine powers the upper cryogenic stage of the Launch Vehicle Mark-3 (LVM3), India’s heavy-lift launch vehicle.
Higher Thrust Testing: Earlier sea-level tests were conducted at 19-tonne thrust, but the latest test validated engine performance at 22-tonne thrust.
Objective of the Test: The test was conducted to support future LVM3 missions using an uprated C32 stage, which requires the CE20 engine to operate at higher thrust.
Test Duration: The engine was tested for 165 seconds at 22-tonne thrust using the Nozzle Protection System (NPS).
Test Results: ISRO reported that engine performance and the test facility operated as expected throughout the test duration.
Challenges of Sea-Level Testing: Cryogenic engines with high area-ratio nozzles face challenges during sea-level testing due to low exit pressure (~50 mbar).
Flow Separation Issue: At sea level, flow separation inside the nozzle can cause vibrations and thermal stress, potentially damaging the engine structure.
Multiple Technology Demonstrations: The tested engine has undergone a record 20 successful hot tests, enabling validation of several key technologies.
Multi-Element Igniter: The engine demonstrated ignition using a multi-element igniter, improving reliability during engine start.