BENGALURU: ISRO on Thursday said it successfully conducted a sea-level thermal test of its CE20 cryogenic engine with a thrust of 22 tonnes at the ISRO Propulsion Complex on March 10.The CE20 engine powers the upper cryogenic stage of the LVM-3 launch vehicle. The latest tests were conducted using a nozzle protection system and a multi-element igniter.Isro said: “Previously, sea level tests using the nozzle protection system were conducted at a thrust level of 19 tons. The latest tests qualified the engine for sea level tests at a higher thrust level of 22 tons. The test lasted 165 seconds.”ISRO plans to use an upgraded version of the C32 cryogenic stage in future LVM-3 missions, providing 22 tons of thrust through the CE20 engine to enhance the rocket’s payload capacity. “Therefore, flight acceptance testing of the CE20 engine also needs to be conducted at higher thrust levels,” Isro said.The space agency said testing the CE20 engine at sea level posed significant challenges due to the engine’s high area ratio nozzle with an exit pressure of about 50 millibars. A critical issue in such testing is flow separation inside the nozzle, which can cause severe vibration and thermal stress at the separation point and potentially damage the nozzle.According to Isro, the cryogenic engine used in the latest trials has successfully conducted a record 20 thermal tests. These tests enable the demonstration of multiple technologies using a single engine.“This includes ignition using a multi-element igniter, ignition margin demonstration Such a mission “We verified Gaganyaan’s engine qualification for propellant tank pressure and prechamber pressure as well as 20-ton thrust level,” Isro added.The tests also verified and verified operation at 22 tons of thrust, bootstrap mode starting of the CE20 engine that enables in-flight restart without starting the system, qualification of domestic turbopump bearings and sensors, and qualification of the nozzle protection system for high area ratio nozzle thermal testing at sea level.ISRO said that throughout the testing process, the engine and test facilities performed as expected.
