ISRO Clears Key 22-Tonne Cryogenic Engine Test Ahead Of LVM3-M7 Mission

The Indian Space Research Organisation (ISRO) has achieved an important pre-flight milestone for its upcoming LVM3-M7 mission, successfully completing the flight-acceptance hot test of the CE20 cryogenic engine at an uprated thrust level of 22 tonnes.

The test, conducted at the Main Engine and Stage Test Facility of the ISRO Propulsion Complex in Mahendragiri, confirmed that the engine systems met all test objectives and performed satisfactorily. The engine will now be refurbished and assembled into the C32 cryogenic upper stage planned for the LVM3-M7 mission, scheduled for the fourth quarter of 2026.

The significance of the test extends beyond one launch. The C32 is an upgraded version of LVM3’s cryogenic upper stage, designed with higher propellant loading and an uprated CE20 engine to enhance the rocket’s payload capability. LVM3, formerly known as GSLV MkIII, is India’s heaviest operational launch vehicle and can carry about 10 tonnes to low Earth orbit.

The test also successfully demonstrated a LOX Tank Pressurisation Module (LTPM) developed for the C32 stage. The specialised subsystem is designed to maintain the required pressure inside the liquid oxygen tank during flight and is planned for use in the Gaganyaan human-spaceflight programme.

The LVM3-M7 mission itself should not be confused with a crewed Gaganyaan flight. Gaganyaan will use a human-rated version of LVM3, with additional systems to ensure crew safety. However, the upgraded C32 technology being developed now is an important part of the launch architecture planned for the programme.

ISRO has also developed a Nozzle Protection System (NPS) that allows the CE20, whose nozzle is designed for high-altitude operation, to undergo hot testing under sea-level conditions. The system can reduce the time and effort required for flight-acceptance testing.

The latest progress reflects ISRO’s strategy of steadily upgrading LVM3 rather than replacing it outright. Future developments, including the SC120 semi-cryogenic stage, could further increase the rocket’s lifting capability, strengthening India’s capacity for heavier missions while supporting its ambitions in human spaceflight.