Chennai, Mar 13 (UNI) ISRO successfully conducted a sea-level hot test of its Cryogenic Engine (CE20) at 22-tonne thrust using the Nozzle Protection System (NPS) and a multi-element igniter on March 10, 2026, at the ISRO Propulsion Complex, Mahendragiri.
Earlier, the sea level tests utilizing the nozzle protection system NPS were being carried out at a 19-tonne thrust level.
The CE20 cryogenic engine powers the upper cryogenic stage of the LVM3 launch vehicle. In order to enhance the payload capability of the LVM3 vehicle, future missions of LVM3 are planned to be operated with an uprated C32 stage with 22 tonne thrust for the CE20 engine.
Accordingly, the flight acceptance test of the CE20 engine was also conducted at the 22-tonne thrust level. The present test successfully qualified the engine’s sea-level operation, with a test duration of 165 seconds at 22-tonne thrust using the NPS. The performance of both the engine and the test facility met expectations throughout the test.
Testing the CE20 engine at sea level poses considerable challenges due to its high area ratio nozzle, which has an exit pressure of approximately 50 mbar. Main concerns during testing at sea-level include flow separation inside the nozzle, which leads to severe vibrations & thermal problems at the flow separation plane, leading to possible mechanical damage of the nozzle.
The Cryogenic engine utilized for this test has undergone a record maximum number of hot tests (20 No.s) successfully, that has enabled the demonstration of several key technologies using a single engine such as engine ignition using multi element igniter, ignition margin demonstration for Gaganyaan over a wide range of propellants tank pressure and pre-ignition chamber pressure, engine qualification for Gaganyaan at 20 tonne thrust level, demonstration & qualification of 22tonne thrust level operation, boot-strap mode starting of CE20 engine without start-up system for enabling re-start in flight, indigenous turbopumps bearings qualification, indigenous sensor qualification and Nozzle Protection System qualification for high area ratio nozzle hot test at sea level.
UNI GV AAB
UNI GV