The Indian government's Department of Space has recently announced the technology transfer of Russian-origin RD-191 semi-cryogenic rocket engines to Indian industry. This move is aimed at enabling Indian industries to manufacture the RD-191 engines in India, which could lead to the possibility of exporting the made-in-India engines and using them as part of India's heaviest rocket, LVM3, thus enhancing its payload carrying capability.
The RD-191 is a high-performance rocket engine that uses kerosene and liquid oxygen as its fuel. The engine is classified as semi-cryogenic, as kerosene can be stored at room temperature, while liquid oxygen has to be stored at super-cooled temperatures below -150 degrees Celsius.
Currently, India operates three kinds of engines on its operational rockets - solid-fuelled, liquid-fuelled, and cryogenic engines that use liquid hydrogen and liquid oxygen stored at super-cooled temperatures.
In an interview with the Russian News Agency Interfax, Andrey Elchaninov, First Deputy Director General of Russian Space Agency Roscosmos, said that India and Russia were discussing the details, characteristics, and scope of deliveries of the RD-191 engines. He expressed his hope to enter into a contract soon, adding that Russia is open to all foreign customers and is not interrupting cooperation with anyone.
While the discussions for the Russian-origin semi-cryogenic engine are underway, the Indian Space agency ISRO is also gearing up for the maiden test of its indigenously-developed semi-cryogenic engine, dubbed the SCE-2000. This engine is a 2000kN engine powered by kerosene and liquid oxygen and is being developed by ISRO's Liquid Propulsion Systems Centre in Thiruvananthapuram.
ISRO has developed a kerosene-based fuel that they call 'ISROSENE' for the SCE-2000. In its latest annual report, ISRO stated that the development of seven out of eight engine subsystems had been completed, and they had realized one ISROSENE propellant tank and two sets of LOX propellant tanks for the semi-cryogenic stage. These have successfully undergone proof pressure tests, and ISRO is now getting ready for the first-ever test of the SCE-2000.
While liquid hydrogen and liquid oxygen are the most efficient cryogenic fuel combinations, storing liquid hydrogen in tanks is an extremely complicated and challenging engineering feat. This is because liquid hydrogen is explosive in nature and expensive to produce. In contrast, rocket-grade kerosene is simpler to handle, as it can be stored at room temperature, and large quantities can be stored in moderate-sized tanks. The low density of liquid hydrogen means that large tanks are required to store even a small quantity of it, thereby increasing the size and mass of the rocket stage.
The technology transfer of RD-191 engines to Indian industry represents a significant development for India's space program, as it could help to reduce its dependence on imported rocket engines and enhance the country's self-sufficiency in the area of space technology. It also opens up the possibility of cooperation between India and Russia in the field of space technology, which could lead to further advancements in the future.
