South Korea's homegrown rocket "Nuri" to conduct second Demo Mission

Updated: Jun 21

Real test satellite model and CubeSats from various institutes are to be launched on this mission.

Infographics by S.I and HDE

On 21st June at 0700 UTC (4 p.m KST), the first homegrown Korean launch vehicle 'Nuri' aka KSLV-2 will attempt a second launch from the Naro Space Center in Goheung-gun, Jeollanam-do. This time, it will place a real artificial satellite in 700 km Sun-Synchronous Orbit.

The Ministry of Science and ICT and the Korea Aerospace Research Institute (KARI) postponed the launch schedule from the original 15th and 16th(backup) to secure safety as strong winds, researchers found technical problems in the level sensor of oxidizer tank on Wednesday after installation of rocket at launch pad, teams decided to postpone the launch and rollback to assembly building for further investigations.

Today, June 20, the transfer and installation of the Nuri completed at the launch pad, the launch team will begin inspection work to prepare for launch, such as umbilical connection and air tightness check for charging power and propellants (fuel, oxidizer)

Nuri F2 installed at Launch Pad-1 at Naro Space Center (Credit; KARI)

During the first launch of the Nuri, carried out at 5 pm KST on October 21, 2021, the launch pad take-off and separation of the 1st, 2nd, and fairings were smoothly successful. Due to the early combustion in a short 475 seconds, the thrust was insufficient, and the dummy satellite could not be placed in the targeted Low-Earth orbit.

The launch committee conducted a two-month-long investigation and concluded that the failure stemmed from the loosening of a device that anchors a helium tank, which was mounted inside the oxidizer tank in the third stage of the rocket.

KARI took technical measures to reinforce the fixing part of the lower part of the helium, leaving behind the regret of 'half success'. On February 25, 2022, Minister Lim Hyesook (Ministry of Science and ICT) mapped out technical improvements to be made to Nuri at the 40th meeting of the Working Committee on Space Development and Promotion.

The Nuri (KSLV-2) is a pure Korean rocket that has completed the entire process of designing, manufacturing, and launching a space launch vehicle with Korean technology with an enormous budget of 2 trillion won ($1.54 Billion USD) for about 12 years from March 2010.

Second Launch Mission of Nuri

Instead of a dummy payload launched on "Nuri" F1 mission, the second launch will be equipped with real artificial satellites for performance verification (PVsat), which includes 4 cubesats, it also carries a 1.3 ton satellite model as primary load. This is because the ultimate goal is to develop a space launch vehicle that can put a 1.5 ton class application satellite into Low Earth orbit (600 to 800 km) and secure launch vehicle technology.

The government plans to enhance reliability by repeatedly launching the Nuri from 2023 to 2027 in line with the goal of securing independent space transport capabilities through the advancement of Korean launch vehicle technology. In this process, through the transfer of launch vehicle technology to the private sector, it is planned to systematically foster a comprehensive space company.

Nuri's Payload adapter mated with 1.3 ton satellite model and PVSAT

Secondary payloads: PVSAT (Performance verification satellite) + Cubesats

Asia Pacific Satellite Inc. has developed PVSAT which supports the 100kg-class small satellite platform and flight software (FSW) development to verify the performance of KSLV-II PVSAT contains five cubesat deployers. Four cube satellites developed by domestic universities will be carried along with payloads to verify the performance of space technology developed in Korea. The mission will be carried out for two years in a solar-synchronous orbit between 600 and 800 km. The fifth deployer will hold a dummy cubesat.

List of Cubesats mounted with PVSAT;

  1. STEP Cube Lab (Space Technology Experimental Project CubeSat Laboratory) is a 6U cubesat developed at Chosun University, Gwangju, South Korea

  2. MIMAN (Monochrome Imaging for Monitoring Aerosol by Nanosatellite) is a South Korean 3U-CubeSat for monitoring fine dust on the Korean Peninsula designed by Yonsei University

  3. RANDEV (Repeater Arrangement & Disaster Early View)) is a South Korean 3U-CubeSat designed by Korea Advanced Institute of Science and Technology (KAIST). RANDEV conducts an earth observation mission to collect potential hazard image data from volcanoes, coasts, and clouds

  4. SNUGLITE is a South Korean 2U-CubeSat designed by the Seoul National University for technology demonstrations and amateur radio communication.

Launch, Deployment Sequence and tracking

All times are approximate

HR/MIN/SEC EVENT (altitude from sea level)

00:00:00 Lift-Off from Naro spaceport (0.1 km)

00:02:07 1st and 2nd stages separate (59 km)

00:03:53 Fairing deployment (191 km)

00:04:34 2nd and 3rd stages separate (258 km)

00:14:57 Separation of PVSAT performance verification satellites (700 km)

00:16:07 Separation of 1.3 ton primary test satellite model (700 km)

(Separation of the performance verification satellite from the target orbit takes about 30 minutes for confirmation of data whether it is separated or not)

Nuri, launched from the Naro Space Center, the rocket performance is tracked from the stations located at Jeju Island and Fukuejima Island in Japan, distance of approximately 100 km.

The Naro Space Center has a tracking radar with a range of 3,000 km and

secures real-time location information, and a telemetry (remote data receiving device) that can check the flight trajectory and operation status of a launch vehicle up to 2,000 km

The expected drop point of stage 1 is about 413 km away from the launch site, and the expected drop point

of stage 2 is about 2,800 km away from the launch site

The fairing separation event will be at an altitude of 191 km, 251 km from the launch site, and expected to splashdown at 1,514 km from the launch site

Development of Nuri

Nuri F1 lift-off from LC-2 Naro Space Center (Credit: KARI)

The Nuri (KSLV-2) development started in 2010 with the design and construction of liquid engine test facilities. It was the stage of assembling a 7t-class small engine and conducting a ground combustion test. This process took 5 years. For four years from 2015, we designed the launch vehicle and engine in detail and succeeded in developing a 75t-class medium-to-large ground engine and test rocket. In November 2018, the first test rocket launched. After four years of making a three-stage launcher system and manufacturing a flight model, it will be launched twice this year and next year. It was a long journey that took a total of 11 years. A South Korean rocket made with state-of-the-art technology hasn't completed overnight. The Naro, which was launched in 2013, and gained experience before the Nuri, was a joint product that received technical cooperation from Russia. Development of the Scientific Rocket (KSR) began in the 1990s. A solid rocket – first produced and tested– with the single-stage KSR-I, followed by the two-stage solid rocket KSR-II. However, induction control technology such as separation has accumulated. The third scientific rocket was the liquid-propelled KSR-III. By developing a 13t-class liquid engine for the first time, it was equipped with essential technologies such as an inertial navigation system, thrust and attitude control, flight termination, nose fairing, and a high-pressure tank. Overcoming these achievements, the Naro (KSLV-1), a 100 kg small satellite launcher, was completed. The liquid engine has also grown to a 30t class. This is enough to put a satellite into orbit. In addition, a launch vehicle capable of placing a 1.5t class practical satellite into low-Earth orbit, the Korean-style space launch vehicle Nuri (KSLV-2), is about to be launched for the second time.

In the long run, the success of Nuri is expected to lead to the realization of Korea's lunar exploration plan. With the recent Korea-US summit as an opportunity, South Korea is the 10th to join the US-led lunar and space exploration project 'Artemis' agreement. Korea will start its own lunar exploration in August 2022 by sending the lunar orbiter Danuri using SpaceX's Falcon 9 launch vehicle. In the longer term, the big goal is to use the Korean launch vehicle Nuri to send to the lunar lander in the 2030s. It means that the mission to open the door to the 'Korean version of the Apollo program' was given to the Nuri.

The Korean Pathfinder Lunar Orbit (KPLO) Danuri, scheduled to launch in August next year, will perform scientific missions for one year at 100 km above the lunar surface if it is safely landed in orbit at the end of that year. The lunar orbiter will be carried on a US launch vehicle, but the ROK government's plan is to achieve the second phase of the lunar exploration (lunar lander) project with a Korean launch vehicle.

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