[Report] Nuri Rocket Undergoes Final Hurdle 'WDR' Before Fourth Launch

2.5-Year Launch Gap Ends with First Private-Led Rocket: "All Systems Go"
Scheduled for Launch Between 12:54 a.m. and 1:14 a.m. in Mid-to-Late November
Main Satellite Deployment 807 Seconds After Liftoff

On September 16, the fourth Nuri rocket, standing 47.2 meters tall and weighing 200 tons, towered over the launch pad at Naro Space Center in Goheung, Jeollanam-do. The rocket, as if aware of the nation's high hopes for space exploration, gazed nonchalantly at the sky, appearing ready to soar into space at any moment.

Despite the scorching sun, numerous researchers and engineers from the Korea Aerospace Agency (KASA), Korea Aerospace Research Institute (KARI), and Hanwha Aerospace tirelessly operated equipment and checked the condition of the Nuri rocket ahead of its mission.

The Nuri rocket, the 4th launch vehicle standing tall at 47.2 meters and weighing 200 tons, at the launch pad of Naro Space Center in Goheung, Jeollanam-do. Provided by the Korea Aerospace Agency.

The Nuri rocket, scheduled for its fourth launch in November, has officially entered the final stages of preparation. The launch date, set for the 26th, will be determined based on the results of the final hurdle: the Wet Dress Rehearsal (WDR).

The WDR conducted by KASA at Naro Space Center involves erecting the launch vehicle on the pad and charging and discharging oxidizer at minus 183°C in a cryogenic environment to verify that the vehicle operates normally under actual launch conditions. This process, which excludes only the payload satellites and the explosives used for stage separation, serves as the final simulation to confirm whether the launch vehicle can successfully carry out its space mission in the same state as during the actual launch.

Projectile moving for launch preparation. Provided by the Space Agency

The Nuri test launch vehicle, which succeeded in its test launch in November 2018, had to undergo technical improvements after an anomaly was found in the pressurization system during the WDR process. As a result, the test launch was delayed by about a month from the originally scheduled date.

Notably, the fourth Nuri launch comes after a 2-year and 6-month gap since the third launch in May 2023. It is also the first launch vehicle for which Hanwha Aerospace, a private system integration company, has overseen the assembly process and participated in launch operations.

Nuriho 4th launch vehicle being erected on the launch pad. Provided by the Korea Space Agency

The payload capacity has also doubled compared to the third launch. The fourth Nuri rocket will carry approximately 1,040 kilograms, including the 580-kilogram Next-Generation Medium Satellite No. 3, 12 satellites in total, and satellite deployment devices. This is more than twice the 500-kilogram payload of the third launch vehicle. For this reason, this WDR is an especially crucial procedure.

Park Jongchan, Director of the Korean Launch Vehicle Advancement Project Group at the Korea Aerospace Research Institute, stated, "We are ensuring the reliability of the launch vehicle by conducting numerous repeated procedures, as if we are carefully testing every step before crossing a stone bridge," adding, "The knowledge accumulated so far is being effectively communicated to researchers through our systems, so there are no issues in work performance due to researcher transfers or the participation of private companies."

Regarding the doubled payload, Director Park explained, "The fourth Nuri rocket can carry over 2 tons, so there is no issue with carrying around 1 ton," and added, "Any launch variables due to the payload can be adjusted through altitude and velocity control during the launch sequence."

Jongchan Park, Director of the Korea Aerospace Research Institute Korea Launch Vehicle Advancement Project Group. Provided by the Space Agency

The WDR began with the erection of the launch vehicle on this day, followed by oxidizer charging and discharging on the 17th, and then moving the vehicle back to the assembly building from the launch pad on the 18th. It will take about a week to analyze the WDR results. If no issues are found, the rocket will be disassembled for component re-inspection and satellite integration, then reassembled and launched in mid-to-late November.

The fourth Nuri launch is scheduled to take place between 12:54 a.m. and 1:14 a.m. on the day of launch, taking into account weather and safety conditions at the site. However, the final launch date will be determined by the Launch Management Committee on the 26th, considering the WDR results and weather conditions.

The fourth Nuri rocket will be launched at an inclination of 97.79 degrees and will carry out its mission in the following sequence: separation of the first and second stages, fairing separation, separation of the second and third stages, separation of the Next-Generation Medium Satellite No. 3, and sequential separation of the 12 secondary payload satellites.

During flight, the fairing, which protects the first-stage rocket and payload, as well as the second-stage rocket, will fall into international waters 430 kilometers, 1,585 kilometers, and 2,804 kilometers from the launch site, respectively. Upon reaching a sun-synchronous orbit at an altitude of 600 kilometers, the main satellite will be deployed 807 seconds after liftoff, followed by the sequential ejection of the 12 CubeSat secondary payloads in pairs at 20-second intervals.

Nuriho 3rd launch vehicle scheduled for launch in May 2023. Provided by Korea Aerospace Research Institute

Yoon Youngbin, Commissioner of the Korea Space Agency, stated, "This fourth Nuri launch is the first to be carried out jointly by KARI and Hanwha Aerospace, marking the beginning of the transition to private-sector leadership," and urged, "Through this WDR, thoroughly check the Nuri rocket's launch readiness, and ensure flawless preparations for the success of the fourth launch during the remaining period."

Lee Sangcheol, President of the Korea Aerospace Research Institute, emphasized, "This WDR will serve as a process to reconfirm the reliability of the fourth Nuri rocket, which has been produced under the leadership of Hanwha Aerospace as the system integrator," and added, "Given that this is the first launch in two years and six months since 2023, we will conduct a more thorough and comprehensive review of the entire launch process."

Meanwhile, the Korea Space Agency plans to launch the fifth (2026) and sixth (2027) Nuri rockets at approximately seven-month intervals following this fourth launch. Starting from the sixth launch, Hanwha Aerospace will take the lead; up to the fifth launch, KARI will handle rocket assembly at Naro Space Center, but from the sixth launch, Hanwha Aerospace will be responsible. Hanwha Aerospace plans to assemble the launch vehicles at the assembly facility being established in Suncheon, Jeollanam-do, and transport them by sea to the launch pad at Naro Space Center.