"Tears Built History"... 30 Years Behind the Scenes of Korea's Space Launch Vehicle Development [Reading Science]

US 'Ankle-Breaking' and Major Powers' Refusal to Transfer Technology
The Story of Over 30 Years Taken by Purely Independent Technology

The Korean launch vehicle Nuriho (KSLV-II), designed and manufactured entirely with domestic technology, is soaring into space with flames bursting from the launch pad at Naro Space Center in Goheung-gun, Jeollanam-do on the 21st. Unlike the first launch, which carried only a dummy satellite with no actual function, the second launch of Nuriho this time included a performance verification satellite and four CubeSats. / Goheung - Photo by Joint Press Corps

[Asia Economy Reporter Kim Bong-su] It took 30 years. Counting from the successful launch of the first Korea Science Rocket (KSR-I) in 1993. A ‘world top 7 space power,’ completed entirely with indigenous technology from start to finish. It surprised the existing space powers that refused to transfer technology to Korea.

This is the story of ‘Nuriho,’ the first independent space launch vehicle that finally succeeded after its second launch on the 21st of last month. Korea, a technology powerhouse known for its ‘ppalli-ppalli’ (hurry-hurry) culture and decades-long dominance in global technology Olympiads, took so long to develop a space launch vehicle and couldn’t even receive common technology transfers. Now, we reveal the behind-the-scenes story of Korea’s 30-year journey in space launch vehicle development.

◇ America’s Obstruction

Recently, the Ministry of Foreign Affairs stepped forward to take charge of science and technology diplomacy, overtaking the Ministry of Science and ICT, the main department. Currently, one division handles diplomacy in energy and science and technology fields, but they plan to expand it to a bureau-level ‘Science, Technology, and Cyber Bureau.’ Advanced technology has become a critical element of national security, and with the opening of the US-China technology hegemony and new Cold War era, there is a plausible rationale. However, some speculate this move is at the behest of the United States. A source in the science and technology sector said, “During negotiations for missile guideline removal and Artemis Accords participation, the Ministry of Science and ICT, the main department, offended the US State Department, the counterpart, and was asked to ‘replace the partner.’”

In the 1980s, the US transferred space rocket technology to Japan but has strongly regulated Korea’s space launch vehicle development until recently through the ‘Missile Guidelines,’ which restrict missile range and fuel types, and the International Traffic in Arms Regulations (ITAR), which block technology transfers. This is cited as the biggest reason why Korea’s space launch vehicle development took over 30 years.

During the Park Chung-hee administration in the late 1970s, when Korea pursued nuclear development, the US strongly regulated it to prevent nuclear proliferation and weapons of mass destruction. In 1979, the US imposed the ‘Missile Guidelines,’ a mere ‘agreement’ between the two countries, blocking Korea’s independent technology research and industrial development. In 2001, the guidelines were revised to limit civilian space launch vehicles to liquid propulsion engines. It prohibited using military rockets or converting civilian rockets for military use. In the 2012 second revision, military missile range was extended from 300 km to 800 km (while maintaining a 500 kg payload), but there was no change for space launch vehicles.

As a result, Korea’s launch vehicle research had to focus on the more difficult liquid fuel engine development instead of the easier solid fuel. Although the first space launch vehicle Naroho (KSLV), which succeeded in 2013, used a solid fuel kick motor in its second stage, it was limited in size due to the upper limit restrictions. The Korean Pathfinder Lunar Orbiter (KPLO) project, scheduled to launch on March 3 by SpaceX, was initially planned to use an indigenous launch vehicle but abandoned the plan because solid fuel use was prohibited. The Nuriho, which succeeded in its second launch last month, was developed with liquid propulsion engines for all three stages.

An expert from the Korea Aerospace Research Institute (KARI) explained in a report, “We have continuously requested the US to strengthen solid propulsion capabilities for space launch vehicles corresponding to the expansion of military missile capabilities, but it was not realized. Since the main focus of the missile guideline revisions was military purposes, the civilian space launch vehicle sector was relatively deprioritized.”

◇ Why Are ‘Foreign PhDs’ Rare at KARI?

At the Daejeon Research and Development Special Zone, KARI is somewhat unique. It is the only research institute where it is difficult to find researchers who have acquired advanced technology and knowledge abroad at prestigious universities such as Harvard or MIT. Other research institutes are filled with master’s and doctoral graduates from top overseas universities and research institutions in their fields, but at KARI, they are very few. The majority of researchers are ‘domestic’ graduates from Seoul National University, KAIST, and others. Although there are occasional graduates from prestigious foreign universities, they are mostly in basic sciences like physics and chemistry, with almost no applied field specialists.

This is because existing space powers strictly control and manage space launch vehicle technology to prevent talent leakage. International students and overseas Koreans who have studied practical and core technologies at NASA or the German Aerospace Center (DLR) are blocked by regulations that classify space launch vehicle technology as top security information, absolutely prohibiting external leakage, making scouting impossible. A somewhat related case is Park Mo, who participated in Korea’s first indigenous fighter jet KF21 Boramae development but was arrested by US judicial authorities and sentenced to 1 year and 6 months in prison for leaking classified information.

After the success of Nuriho’s second launch, space powers have already started to keep Korea in check. Some institutions have refused exchange training programs that were conventionally conducted for technology and personnel exchange. A KARI researcher had planned a one-year training at DLR and was fully prepared, but after Nuriho’s success, the training was suddenly canceled.

Poor working conditions also make it difficult to recruit foreign PhDs. Located in Daejeon, it is less preferred by overseas-educated professionals. The working conditions are harsh; about ten years ago, during the early stages of launch vehicle research and development, a team leader-level researcher died from overwork at a young age. Long-distance business trips are common. The round trip from Daejeon, where the office is located, to Naro Space Center, responsible for launch vehicle assembly and operation, is 600 km, and to Sacheon, Gyeongnam, where engine and parts development, production, and testing are conducted, is 400 km. Since 2010, due to two Naroho launch failures, the entire research staff’s salaries were cut, ranking KARI among the lowest of 25 national science and technology research institutes.

Shin Myung-ho, chairman of the KARI labor union, lamented, “Most people who retire from other national research institutes usually go on to become university professors. But here, because of poor working conditions and low salaries, many move to venture or small and medium-sized enterprises, not startups.”

◇ Tears Shed Over 2mm Steel Plates

The most difficult task during Nuriho’s development was unexpectedly ‘welding.’ Welding and processing special alloys about 2.5 mm thick to make propellant tanks was not simple. The research team later confessed that the external perception that “Korea is the world’s strongest shipbuilding nation with the best welding technology” was a heavy burden.

Nuriho’s propellant tanks reach a maximum height of 10 m and a diameter of 3.5 m. However, their thickness is only 2.5 to 3.0 mm. They are similar to an enormously large beverage can. The problem is that despite being so thin, the tanks must withstand the pressure and loads applied during the escape from Earth’s atmosphere while supporting Nuriho’s 200-ton weight. The inside of the propellant tanks is designed with a dense triangular lattice structure, an isotropic lattice structure. Each side of the triangles supports the weight of the fuel and reduces sloshing, the phenomenon of fuel movement inside the tank. Initially, the team struggled even with the design, but through repeated computer simulations, they devised an optimized structure.

Other difficult technical challenges included maintaining pressure and injecting fuel and oxidizer into the combustion chamber via turbopumps without mixing in zero gravity, the ‘regenerative cooling’ method that creates stripes on the nozzle and uses fuel internally as a coolant to withstand injection heat exceeding 3000 degrees Celsius, technology to organically control four engines using hydraulic actuators to manage the launch vehicle’s direction, angle, and attitude, and solving engine combustion instability problems. Ko Jung-hwan, head of KARI’s launch vehicle development division, cited the difficulties in developing the propellant tanks as one of the hardest moments during a briefing immediately after the successful launch on the 21st of last month. He recalled, “Without establishing the propellant tank development process, the overall picture of the launch vehicle was unclear. It was a dark period when we couldn’t see ahead, thinking ‘when will this be solved and when will we make it?’”

◇ The Real Reason Is ‘Money’

Although the atmosphere has somewhat changed with Nuriho’s success, the government’s will and direction toward becoming a full-fledged space launch vehicle-owning country remain fluid. Currently, Nuriho’s performance, capable of placing a 1.5-ton satellite into low Earth orbit (altitude 600?800 km), is inferior to that of US private companies. This was a decisive reason why the government postponed the preliminary feasibility study application for the 2 trillion won next-generation launch vehicle development project last June. Critics say it was a ‘wait-and-see’ move ahead of the presidential election, suggesting that the next administration should decide. The implication was to propose research on ‘quantum leap’-level technological innovation because even if Korea works hard to upgrade over the next 10 years, competing countries and launch vehicles will have advanced further.

With a launch cost per kilogram of $32,595 (2018 standard), Nuriho cannot compete with SpaceX’s Falcon 9, which costs only $2,000 per kilogram. To be recognized as a country ready to open a full-fledged space development era, Korea must at least have the capability to independently launch large satellites into geostationary orbits and conduct deep space exploration to the Moon, asteroids, and even Mars. It is also an essential condition to participate in the Artemis project, led by the US and its allies aiming for lunar landing exploration and base construction, to reap its benefits.

The government is currently reviewing plans to upgrade Nuriho by developing 100-ton class liquid engines, thrust control, and rocket reuse technology for recovery. However, citing ‘liquidity’ issues due to the lack of long-range launch vehicles, the asteroid Apophis exploration plan has been effectively ‘abandoned.’