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South Korea’s Nuri rocket, also called KSLV-II, is a three-stage launch vehicle powered by liquid-fuel engines. Four engines drive its first stage, a single engine powers the second, and a smaller engine completes the third. Korea Aerospace Research Institute (KARI) gives its reference capacity as a 1.5-ton application satellite to a 600–800 km sun-synchronous orbit—not a payload figure that applies to every orbit.
How Nuri’s three stages work
A launch vehicle uses stages so it can discard sections that have completed their part of the ascent. After a stage finishes, it separates and the remaining vehicle continues under the next stage. KARI identifies Nuri as a three-stage vehicle; Korea AeroSpace Administration (KASA) reported that all three stage engine combustions and fairing separation were completed on the fourth launch before payload deployment. The official sources cited here do not provide a complete second-by-second flight timeline.
First stage: four 75-ton-class engines
Nuri’s first stage clusters four 75-ton-class liquid engines. KARI says the cluster produces 300 tons of thrust. The combined engines provide the initial push from the launch pad and through the early ascent.
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The second stage uses one 75-ton-class engine. It continues accelerating the vehicle after the first stage separates.
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Third stage: one 7-ton-class engine
The third stage uses one 7-ton-class liquid engine to carry the payload toward its intended orbit after the lower stages have done their work. KARI’s engine information identifies liquid oxygen and kerosene tanks on this stage.
What happens inside a Nuri engine
KARI describes the engine as a system that burns fuel and oxidizer in a combustion chamber. The resulting high-temperature, high-pressure gas escapes through a nozzle to produce propulsion. A turbopump feeds fuel and oxidizer to the chamber at high pressure, while a gas generator produces gas to drive the turbopump turbine. KARI’s Nuri engine overview explains these components and the engine arrangement.
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Engine testing behind the design
KARI reports that between April 2016 and November 2020, it assembled and tested 25 units of the 75-ton-class engine. Those tests totaled 168 firings and 16,690 seconds of cumulative burn time; the longest continuous burn recorded for one engine was 260 seconds. These are historical totals through November 2020, not lifetime totals.
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KARI also reports 11 units of the 7-ton-class engine, 89 tests and 16,385.7 seconds of cumulative burn time. The page does not specify the date range for those totals, so they should not be treated as current lifetime figures.
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How much payload can Nuri carry?
KARI states that Nuri can place a 1.5-ton application satellite into a 600–800 km sun-synchronous orbit. The altitude and orbit type are essential qualifications: the figure is not an orbit-independent maximum payload. See KARI’s Nuri vehicle overview for the stated capability.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.A flown example: Nuri’s fourth launch
On November 27, 2025, Nuri’s fourth launch deployed CAS500-3 and 12 CubeSats to a target orbit of 600 km, for 13 payloads in total. KASA reported successful combustion of all three stage engines and successful fairing separation. This mission shows Nuri carrying a particular payload manifest to a particular target orbit; it does not replace KARI’s 1.5-ton reference-capacity statement or establish a new maximum. KASA’s fourth-launch report describes the flight.
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Nuri’s launch record and the fifth-flight schedule
KARI records Nuri’s first flight test on October 21, 2021. The rocket reached its target altitude but did not attain the target velocity needed for orbit insertion. KARI lists successful launches on June 21, 2022, May 25, 2023 and November 27, 2025. In its account of the 2022 flight, the Ministry of Science and ICT said the performance verification satellite reached its target orbit after the three stage engines burned as planned and the fairing separated. The ministry’s launch account gives details of that mission.
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Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →In August 2026, KASA announced that Nuri’s fifth launch was scheduled for October 7, with a backup period of October 8–14. The planned manifest was five microsatellites and 10 CubeSats. KASA’s announcement is a schedule, not confirmation of the flight outcome: the official material cited here does not establish whether the launch occurred or what it achieved. See KASA’s August 27 schedule announcement and its August 25 approval announcement.
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