Nuri rocket to carry 15 satellites into orbit, ushering in South Korea's constellation era

South Korea's homegrown Nuri rocket will lift off on Oct. 7 carrying 15 satellites, marking what officials say will be a pivotal shift in the country's space program — from operating individual satellites to running a coordinated constellation. For the first time, five ultra-small satellites will be deployed simultaneously into orbit.

The Korea AeroSpace Administration and the Korea Aerospace Research Institute held a press briefing Tuesday on the fifth Nuri launch, disclosing the payloads' missions and the current state of launch preparations.

The fifth Nuri mission will carry a total of 15 satellites: five units (Nos. 2 through 6) of the primary payload NeonSat, an ultra-small cluster satellite series, along with 10 CubeSats as secondary payloads. It is the largest satellite payload ever carried by Nuri and the first time the rocket has flown with multiple primary payloads.

The mission's central objective is to deploy all five NeonSat units sequentially into sun-synchronous orbit. Each satellite weighs less than 100 kilograms and carries an electro-optical camera capable of 1-meter-resolution black-and-white imagery and 4-meter-resolution color imagery. The constellation is designed to support national security as well as disaster response — including wildfires and floods — through high-frequency, high-precision Earth observation.

Deploying multiple satellites in succession required new engineering solutions. Nuri will use a low-shock satellite separation device to reduce the impact forces generated during release. The five NeonSat units will be ejected at 35-to-40-second intervals in different directions to prevent in-orbit collisions.

A dedicated separation sequence will also control the attitude of the rocket's upper stage throughout the process. After all satellites — including the CubeSats — have been released, the upper stage will perform an avoidance maneuver to prevent any collision with the deployed payloads.

NeonSat is ultimately planned as a 10-satellite constellation distributed across two orbital planes. The five first-batch production units going up on this fifth launch will be joined by five more second-batch units via the sixth Nuri launch in 2027. Once the full constellation is in place, it will image the Korean Peninsula at least three times a day and revisit any given point within 24 hours.

Ten CubeSats will also ride along. They were developed by 10 research and development organizations spanning universities, local governments and domestic companies.

The CubeSats will carry out a range of public-interest missions: verifying the performance of domestically produced components and parts in the space environment (the Korea Aerospace Research Institute's domestic space-verification platform No. 2), surveying the low-Earth-orbit space environment (GBISat, KAIST), monitoring ocean debris currents around Jeju Island (PURSAT-02, Quaternion), and analyzing fine-dust trends and sources (Ulysses, the Unmanned Exploration Research Institute).

Each developing organization plans to validate its own technologies, components and parts in actual space conditions and apply the results to future development and applications.

"This fifth launch is the first to carry multiple primary payloads and the largest satellite payload Nuri has ever flown," said Park Jae-seong, head of the space transportation division at KASA. "If the satellites operate successfully, it will mark an important turning point in which South Korea's satellite development leaps into mass production and constellation operations."

Final assembly of Nuri 5 at the Naro Space Center in Goheung, South Jeolla Province — which began June 29 — is now in its closing stages. All 15 satellites have been loaded onto the rocket's upper stage, and full vehicle assembly is expected to be completed by the end of this month. After a final inspection on Oct. 5, the rocket will be transferred to the launch pad on Oct. 6 if no issues are found.

The scheduled launch date is Oct. 7. The exact launch time will be confirmed on the day by the launch management committee.

"The fifth Nuri launch is South Korea's first constellation satellite launch and an important turning point in the country's leap toward mass production and constellation operations," said Oh Tae-seok, administrator of KASA. "We will spare no effort in our preparations until the very last moment to ensure a successful launch."