[Nuriho 3rd Launch] The Development History of 'Tears and Glory'

With Korean Indigenous Technology, 1.95 Trillion Won Invested Over 13 Years
Despite Challenges, Ultimately Achieved Success

The first Korean indigenous space launch vehicle, Nuriho (KSLV-II), is a three-stage space launch vehicle independently developed with our technology over 13 years since 2009, costing more than 1.957 trillion won. It has been a history of tears and glory.

The Korean launch vehicle Nuriho (KSLV-II), designed and manufactured entirely with domestic technology, is soaring into space with flames erupting 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 functionality, the second launch of Nuriho this time included a performance verification satellite and four CubeSats. / Goheung = Photo by Joint Press Corps

It is 47.2 meters long, equivalent to the height of a six-story building. Its maximum diameter is 3.5 meters, weight is 200 tons, target orbit is 600~800 km, and maximum payload is 1.5 tons. The first stage consists of four 75-ton liquid engines producing 300 tons of thrust. The second stage has one 75-ton class liquid engine, and the third stage has one 7-ton class liquid engine. The fuel is kerosene (special aviation kerosene), and the oxidizer is liquid oxygen.

Throughout the 13 years of development, it went through numerous trials and tribulations. Technology was acquired during the development of Naroho with Russia until 2013. It is a well-known 'unofficial history' that an old real engine that Russia accidentally handed over to us was a great help. However, with even the United States, our greatest ally, not providing assistance, the engineers at the Korea Aerospace Research Institute who embarked on independent development endured a march of hardship. It was a 'headfirst into the unknown' approach, resulting in many trial-and-error attempts. In particular, the engine under development exploded due to resonance phenomena, and synchronizing four engines together was a top-level difficulty that troubled the researchers.

During the first launch in October 2021, the flight was normal but failed to place the satellite mock-up into orbit. Although it needed to maintain a speed of over 7.5 km/s, the helium charging device inside the fuel tank became loose, causing insufficient thrust at the final stage. The second launch in June last year faced critical moments with two delays: once due to strong winds and once due to internal sensor failure. However, it ultimately succeeded by placing a performance verification satellite and four CubeSats into orbit.

The third launch was originally scheduled for 6:24 PM on the 24th. However, about three hours earlier, around 3 PM on the same day, the communication system operating the helium injection valve malfunctioned, causing a one-day delay and some commotion.

Nevertheless, the level of hardship Nuriho has experienced is actually quite mild on a global scale. Even NASA, which possesses the world's top technology, and SpaceX often struggle handling launch vehicles made of tens of thousands of precision parts. NASA recently faced multiple delays due to malfunctions such as fuel leaks while launching the Space Launch System (SLS), considered the most powerful launch vehicle in history. SpaceX also experienced several explosion accidents during the development of Starship.

This content was produced with the assistance of AI translation services.