On Thursday, the Indian Space Research Organisation (ISRO) announced a major achievement in propulsion technology with the successful sea-level test of the CE20 cryogenic engine. This milestone is crucial for future missions like Gaganyaan, India’s first human spaceflight mission. The test was conducted on November 29 at ISRO’s Propulsion Complex in Mahendragiri, Tamil Nadu.
The CE20 engine powers the upper stage of the Launch Vehicle Mark-3 (LVM3) and has now demonstrated its ability to restart, a vital feature for advanced space missions. During the test, the engine showcased an upgraded nozzle area ratio of 100.
ISRO highlighted that the CE20 engine, developed by the Liquid Propulsion Systems Centre, operates at a thrust level of 19 tonnes and has already been used in six successful LVM3 launches. For the Gaganyaan mission, the engine was enhanced to produce a thrust of 20 tonnes, with plans to further increase it to 22 tonnes for the future C32 stage, improving the LVM3’s payload capacity.
A key focus of this test was evaluating a multi-element igniter to enable the engine’s restart capability. Restarting cryogenic engines is challenging, especially under vacuum conditions, but ISRO has successfully demonstrated this in previous ground tests.
To address issues like flow separation in the nozzle, which can cause vibrations and thermal damage, ISRO introduced a new “Nozzle Protection System.” This innovation offers a simpler and more cost-effective alternative to traditional high-altitude testing methods.
The CE20’s high nozzle area ratio results in an exit pressure of around 50 millibars, making sea-level testing difficult. However, the new system has resolved these challenges, streamlining future engine acceptance tests.
