The Indian Space Research Organisation (ISRO) has successfully completed the flight-acceptance hot test of its CE20 cryogenic engine at an uprated thrust of 220 kN. The test is aimed at increasing the payload capacity of the LVM3 launch vehicle and supporting upcoming missions under the Gaganyaan programme.

The test was conducted on September 9 at the ISRO Propulsion Complex (IPRC) in Mahendragiri, Tamil Nadu. The space agency announced the development on Thursday through a post on X. ISRO said, “Flight acceptance hot test of CE20 cryogenic engine earmarked for the C32 upper stage of upcoming LVM3 mission at uprated thrust conditions of 220kN is successfully carried out at ISRO Propulsion Complex, Mahendragiri on September 09, 2026.”

During the test, ISRO also successfully demonstrated the performance of the LOX Tank Pressurisation Module (LTPM). The module is designed for the C32 stages, which will be used in Gaganyaan missions.

The CE20 engine powers the upper cryogenic stage of the LVM3 launch vehicle. ISRO is working to operate future LVM3 missions with an uprated C32 stage. The stage will use the CE20 engine at a 22-tonne thrust level. This upgrade is expected to improve the vehicle’s payload capability.

The latest test follows a sea-level hot test of the CE20 engine conducted in March at the Mahendragiri facility. That test was also carried out at the 22-tonne thrust level. ISRO used a Nozzle Protection System and a multi-element igniter during the test.

The March test focused on qualifying the CE20 engine for sea-level operations at the higher thrust level. ISRO had said that both the engine and the test facility performed as expected during the 165-second test.

Testing the CE20 engine at sea level is technically challenging due to its high-area-ratio nozzle. The design results in low pressure at the nozzle exit during ground testing. Flow separation inside the nozzle can lead to severe vibrations and thermal stresses and pose risks to the structural integrity of the nozzle.

The successful flight acceptance hot test now takes the uprated C32 stage closer to operational use on upcoming LVM3 missions. It also supports ISRO’s broader efforts to strengthen the launch vehicle’s capabilities for future missions, including Gaganyaan.

The development comes days after ISRO successfully launched the Advanced Earth Observation Satellite-05 (EOS-05) aboard the GSLV-F17 on September 5. The launch took place from the Satish Dhawan Space Centre in Sriharikota.

ISRO Chairman V Narayanan called the mission a significant achievement. The 2,367-kg satellite was successfully placed in its intended orbit. Narayanan said the satellite would become India’s first dedicated imaging satellite from geosynchronous orbit once it is operationalised.