South Korea: debut of the Nuri launcher without a successful conclusion

The three-stage KSLV II rocket “Nuri” (translated from World) was launched from South Korea’s Naro space center in Goheung Province, less than 500 kilometers south of Seoul, at 5:00 p.m. local time (10:00 a.m. in Poland). The aim of the South Korean test was to place a dimensional-mass mock-up in orbit corresponding to a satellite payload of 1.4 tons.

Nuri is the first space rocket designed and built entirely (with the potential of its own research and development centers and industry) by South Korea. For most of the flight, the test seemed to be model-based – in the end, however, the basic goal of introducing a dummy satellite load into the planned orbit was not achieved.

The rocket made it far, but failed to put a mock satellite in orbit, reported the South Korean news agency Yonhap, citing the country’s president, Mun Dze In. More details about the course of the test were provided by the Minister of Science and ICT, Lim Hye-suk, who indicated that although the rocket reached a height of 700 km above the Earth’s surface, there were probably problems with the propulsion of the third rocket segment (it worked 475 seconds instead of the necessary 521 seconds). Ultimately, the thrust shortage caused that the load did not reach the required orbital speed, which should be 7.5 km / s at a given altitude.

Despite this result, representatives of the South Korean government emphasized that the overall course of the test fills them with pride and optimism. “Unfortunately, we did not fully achieve our goal, but in the first flight we achieved a very impressive achievement,” commented the President of South Korea. “The fact that the first stage, the segment separation mechanism and the second stage worked flawlessly, and the third segment itself fired and worked for a long time, is an achievement in itself,” Minister Lim Hye-suk said during a press briefing.

So far, the South Korean authorities have allocated nearly 2 trillion won (approximately $ 1.8 billion) to the development of the KSLV II system. This amount also includes the creation of an appropriate, adapted starting point on the territory of the country.

The first launch of the Nuri rocket – October 21, 2021. KARI []

However, this is not the first such project in South Korea. In 2013, the first national space rocket, Naro, was successfully launched from there. However, it was not a fully native structure – its first stage was purchased and built in Russia.

KSLV II “Nuri” is already a system entirely built in South Korea. It is a large structure with a weight of nearly 200 tons. It is to be able to carry a 1.5-ton utility satellite to a low orbit around the Earth with altitudes in the range of 600-800 km above the Earth and even 2600 kg of the object at an altitude of 300 km. The three-stage launch vehicle uses four Stage 1 engines (KRE-075 SL – liquid propellant), one Stage 2 engine (KRE-075 – vacuum capable) and a minor peak stage drive unit (KRE-007). They are all powered by aero gas turbine fuel (Jet A-1), burned in the presence of liquid oxygen.

The use of Nuri is to support mainly national satellite launches, which have so far been commissioned to foreign operators. At the outset, it will be a few Earth observation satellites, primarily from the KOMPSAT series, enabling reconnaissance from the LEO level. In addition, Nuri will be South Korea’s first rocket, which will allow it to present its commercial services offer to domestic and foreign users. The cost of a single mission is estimated at approximately USD 30 million, which is at a competitive rate compared to Asian counterparts. Such an offer is to be of particular interest to the countries of Southeast Asia.

The first launch of the Nuri rocket – October 21, 2021. KARI []

It is also emphasized that Nuri is an evolving structure – subsequent versions of the system will offer improved performance and capabilities in pursuit of more ambitious South Korean plans – especially in terms of building a satellite navigation system and the Moon exploration project (the idea of ​​sending orbiters and landers). Until recently, it was expected that a significantly improved version of the Nuri would launch the Korean lunar lander by 2030.

The first flights of the Korean Nuri rocket were originally planned for 2018. For several years, however, there were technical problems, resulting in changes to the first stage assembly process and delays in the procurement of parts. This forced Korean specialists to postpone the schedule several times.

According to recent announcements, the first operational Nuri mission was to take place in May next year – including the launch of a 200-kilogram satellite. After the rocket’s unsuccessful debut, it is not certain whether it will actually be an operational flight.

The Yonhap agency notes that South Korea’s missile development program was previously restricted by the United States’ missile restriction, which was introduced in 1979. However, both countries agreed to lift the restrictions during the summit in May this year.