Fired for 100 seconds… Domestic technology behind the one-stage rocket that broke through difficulties [영상]

Naroju Center in Oenaro-do, Goheung-gun, Jeollanam-do at 3 pm on the 25th. Four 75t class liquid engines emit bright yellow fire at the same time. The powerful flames covered the quiet island with white smoke and vibrations.

The Korea Aerospace Research Institute (HANG Woo-yeon) verified the performance of the first-stage rocket, the lowest stage, of the first launch vehicle (Nuri, KSLV-II) developed with domestic technology. “The result of the combustion test was successful,” Hang Woo-yeon announced. It means that there was no particular problem after 100 seconds of burning test using the same automatic launch software as the actual launch scheduled for next year. The time has come for the Korean launch vehicle to travel in space.

The reason the launch makes sense on this day is that the first-stage rocket is the most technically difficult to verify. The Nouriho is a three-stage liquid rocket with a weight of 1500 kg and a length of 47.2 m. The first, second, and third-stage rockets are stacked from below. Among them, the second-stage rocket has already been verified, and the third-stage rocket has also finished making flight models.

The problem was the first-stage rocket that produced the greatest thrust (the force to push and lift the weight). Unlike the second-stage (75t class) and third-stage (7t class), which use only one engine, the first-stage rocket has four 75t class liquid engines tied together. The projectile can be controlled only when four engines are ignited at the same time as if they were one body, and their output and performance were almost the same.

The need for such a tricky technology even delayed the launch of the Nuri. An official from Hang Woo-yeon said, “In December of last year, we decided that the company that produced the rear fuselage of the first-stage rocket was lacking in technology and replaced it with Korean fiber. It was for this reason that the National Space Commission delayed the launch of the Nuri, which was scheduled for launch this month, by one year. The Ministry of Science and ICT said, “The development of the first stage of the launch vehicle has affected the schedule adjustment.”

The technology of domestic companies is behind the success of the combustion test through twists and turns.

Hanwha Aerospace took over the assembly work for the 75t-class engine that emitted flames on this day. Major engine parts are also manufactured by 100% domestic companies. The parts (pyro starter) used to ignite the flame were supplied by Hanwha Co., Ltd. Explosives Division. Liquid oxygen and kerosene (kerosene) are the powers that make Nuriho rise in the air. The turbo pump sucks in the liquid oxygen in the oxidant tank and kerosene in the fuel tank, which was manufactured by Hanwha Aerospace and SNH.

The fuel and oxidant absorbed by the turbopump explode in the combustor, which acts as a cylinder in a vehicle. It was Vitzronextech that made the combustor. In addition, the engine supply system, in which various parts that supply power and oxidizing agents to the engine such as valves, igniters, and piping, are gathered, is a joint product of six domestic companies including Space Solution, Hy-Lok Korea, NK and Samyang Chemical.

The fuel exploded from the combustor generates thrust and floats the rocket into the air. An official in the aviation industry explained, “The success of the combustion test for 100 seconds proves that the domestic companies’ high-temperature heat-resistant material technology, precision processing technology, and engine technology are world-class.”

A structure containing such complex parts was also made by a Korean company. Doowon Heavy Industries & Construction made a structure (tank connection) that connects the oxidant tank and fuel tank manufactured by KAI. S&K Airways and Fiber Korea participated in the production of parts connecting these structures.

The reverse propulsion motor that pushes the second-stage rocket in the direction opposite to the direction in which the second-stage rocket is separated from the first-stage rocket is provided by Hanwha Corporation. made.

The combustion test of the first stage Nuri-ho rocket is conducted three times. Following the 30 second combustion test last month, it succeeded until the 100 second combustion that day, leaving only the final test. Anti-Woo-Yeon plans to do a 130 second combustion test by the end of next month. If successful, the first stage rocket development is completed.

After successful development of the first-stage rocket, the Nuri will be tested and launched in October this year. The test launch was performed by launching only the launch vehicle without the satellite (mounted vehicle) to verify that a payload weighing 1.5 tons could be put into orbit. It is a verification process. If the test launch is successful, the Nuri will fly a test satellite in May next year. If this is successful, the Nuri is expected to fly into space with the next generation of small satellite 2 in the future.

Minister of Science and Technology Choi Ki-young said, “This combustion test passed the most technically difficult test before launching the Nuri. We will do our best in the future development process so that the Nuri can be launched without a hitch.”

Reporter Moon Hee-cheol [email protected]