CHENNAI: India’s GSLV-Mark III project aimed at carrying four-tonne payloads, including future manned missions, has got a boost with Isro successfully test-firing on ground CE-20, the first indigenous high-thrust cryogenic rocket engine for more than its full duration.

Isro on Monday confirmed that the test was conducted at the Isro Propulsion Complex at Mahendragiri in southern Tamil Nadu for 800 seconds, which is 25% more than the burn duration of the engine during flight. On April 28 this year, Isro did the first full-duration ground test of the engine, for 645 seconds.

Isro spokesperson Deviprasad Karnik told TOI that the next step would be high-altitude tests by simulating low pressure atmospheric conditions on ground to see how the engine behaves. “After the tests we will go in for the stage assembly. GSLV-Mk III is expected to make its first flight by the end of 2016,” he said.

India has so far used six of the seven cryogenic engines procured from Russia and needs indigenous engines to fly GSLVs to propel its future space missions.

India had developed an indigenous cryogenic stage called CE-7.5 with an engine thrust of 7.5 tonnes. Compared to this, CE-20 will have a higher thrust of 19 tonnes and will be capable of carrying satellites that weigh up to four tonnes.

The first flight of a GSLV with the indigenous CE-7.5 cryogenic engine on December 25, 2010 was a failure, but on January 5, 2014 GSLV-D5 (Mk II) used the engine to successfully put in orbit communication satellite GSAT-14 which weighed 1,982kg.

Cryogenics, the science of very low temperatures, has remained a tricky affair for rockets scientists across the world. A cryogenic engine uses hydrogen as fuel, stored at minus 253 degrees Celsius and liquid oxygen as oxidizer at minus 183 degrees Celsius.

The USSR (later Russia) and the US were pioneers in this section of rocketry, later mastered by China, Japan and the European Space Agency.

The engine design was totally in-house effort with experts from different fields like fluid dynamics, combustion, thermal, structural, metallurgy, fabrication, rotor dynamics, control components, etc working together. The fabrication of major subsystems of the engine was carried out through Indian industries. Assembly and integration of the engine and testing were carried out in ISRO Propulsion Complex (IPRC), a unit of Isro, the organisation said in a statement on Monday.

The recent successful endurance hot test of the first high thrust cryogenic engine was the tenth test. The performance of the engine closely matches with the pre-test prediction made using the in-house developed cryogenic engine mathematical modelling and simulation software, Isro said.

Prior to engine realisation, a series of subsystem level tests were carried out to independently evaluate the design of major subsystems like the turbo pumps, thrust chamber, gas generator and flow control components.

