BENGALURU: The Indian Space Research Organisation (Isro) has carried out the flight acceptance hot test of the indigenous CE20 cryogenic engine that will power the upper stage of the next LVM3 launch, designated LVM3-M7.Isro is, however, yet to commit to a launch date for the LVM3-M7 mission. The latest test, conducted on July 6 at the Isro Propulsion Complex in Mahendragiri, marked the first time the space agency used a newly developed Nozzle Protection System (NPS) during a flight acceptance test. Isro said the engine and the new system performed satisfactorily, clearing the way for the engine to be refurbished and integrated with the C32 cryogenic stage being prepared for the mission.During the test, the engine was operated at a thrust level of 19.5 tonnes for 45 seconds before being ramped up to its maximum rated thrust of 22 tonnes for another 25 seconds. According to Isro, the results confirmed the satisfactory performance of both the engine systems and the NPS.The CE20 engine powers the cryogenic upper stage of the LVM-3, India’s heaviest operational launch vehicle. Developed indigenously, the engine is qualified to operate across a thrust range of 19 to 22 tonnes and has successfully flown on eight consecutive LVM-3 missions. These include Chandrayaan-2, Chandrayaan-3 and three commercial launches. The engine has also completed the human-rating qualification required for use in the Gaganyaan programme, India’s first human spaceflight mission.“The newly introduced Nozzle Protection System is designed to enable testing of the CE20 engine fitted with its full area-ratio 100 nozzle under sea-level conditions. Until now, such tests required complex high-altitude test facilities to simulate the near-vacuum conditions in which cryogenic upper-stage engines operate,” Isro said.Isro said the new system simplifies these procedures, reduces the resources needed for engine testing and enables longer-duration tests. The agency had earlier developed and validated the Nozzle Protection System on a qualification engine through multiple test campaigns before deploying it for a flight acceptance test.The successful demonstration is expected to streamline future acceptance testing of the CE20 engine while supporting upcoming LVM3 launches, including missions under the Gaganyaan programme.