BENGALURU: The Indian Space Research Organisation (ISRO) on Thursday announced the successful sea-level hot test of its CE20 cryogenic engine at a thrust level of 22 tonnes. The test was conducted at the ISRO Propulsion Complex on March 10.
The CE20 engine powers the upper cryogenic stage of the LVM-3 launch vehicle. According to ISRO, the latest trial was carried out using a nozzle protection system along with a multi-element igniter.
“Earlier, sea-level tests using the nozzle protection system were conducted at a thrust level of 19 tonnes. The latest test validates sea-level testing of the engine at the higher thrust level of 22 tonnes. The test lasted 165 seconds,” ISRO said.
The space agency plans to use an upgraded C32 cryogenic stage in future LVM-3 missions, with the CE20 engine delivering 22 tonnes of thrust to enhance the rocket’s payload capacity.
“As a result, the flight acceptance test of the CE20 engine will also need to be conducted at the higher thrust level,” ISRO added.
ISRO noted that testing the CE20 engine at sea level presents significant technical challenges because of the engine’s high area-ratio nozzle, which has an exit pressure of about 50 mbar. One of the main concerns during such tests is flow separation within the nozzle, which can lead to severe vibrations and thermal stress at the separation point and potentially damage the nozzle.
The cryogenic engine used in the latest trial has undergone a record 20 successful hot tests so far, enabling the demonstration of several technologies using a single engine.
“These include ignition using a multi-element igniter, ignition margin demonstration for the Gaganyaan mission across a wide range of propellant tank pressures and pre-ignition chamber pressures, and engine qualification for the Gaganyaan mission at a 20-tonne thrust level,” ISRO said.
The tests also demonstrated and validated operation at 22 tonnes of thrust, the bootstrap-mode start of the CE20 engine without a start-up system to enable in-flight restart, the qualification of indigenous turbopump bearings and sensors, and the nozzle protection system for hot tests of a high area-ratio nozzle at sea level.
ISRO said the engine and the test facility performed as expected throughout the 165-second test duration.
