The fourteen satellites Nuri placed in orbit on its fifth launch

🔭Five identical satellites#

NEONSAT 2 through 6, South Korea's first constellation launch

The primary payloads on this launch were satellites 2 through 6 of the NEONSAT micro-satellite constellation. All five were mass-produced to carry out the same mission. KASA described this as South Korea's first satellite constellation launch. NEONSAT comprises ten satellites in total, designed to operate as one group. This launch sent half of them into orbit.

1 m monochrome, 4 m color#

Observation satellites weighing less than 100 kg each

Each NEONSAT satellite weighs less than 100 kg. It carries an electro-optical camera with approximately 1 m monochrome and 4 m color resolution. NEXTSat-2, the primary payload on the third launch, weighed 180 kg. KASA said NEONSAT imagery would be used for national security and responses to disasters such as wildfires and floods.

Ten satellites, three times a day#

Two orbital planes and repeat imaging within 24 hours

The ten NEONSAT satellites will be distributed across two orbital planes and operated as a single constellation. The first batch of five mass-produced satellites went up on this launch, and the constellation will be complete when the second batch of five goes up on the sixth launch next year. From then on, it will be able to image the Korean Peninsula at least three times a day and revisit the same location within 24 hours.

Mass production led by KAIST#

With KARI and Satrec Initiative

With support from KASA, the KAIST Satellite Technology Research Center (SaTReC) leads development of the micro-satellite constellation, with participation from Korean industry, academia and research organizations, including KARI and Satrec Initiative. The project goes beyond building the satellite platforms. It also includes developing ground systems to control multiple satellites and receive imagery, along with systems for image calibration, validation and use.

🧩Deploying satellites without collisions#

A low-shock separation system and intervals of 35 to 40 seconds

Nuri's separation hardware and procedures were modified to deploy the constellation satellites. A new low-shock satellite separation system was installed to reduce the shock generated when satellites detach. The procedures also called for the five NEONSAT satellites to separate in different directions at intervals of 35 to 40 seconds to prevent collisions.

Why the launch was at 12:25 p.m.#

A launch time set by the satellites' mission

At a Launch Management Committee meeting on August 27, KASA set the launch window between 12:23 p.m. and 1:23 p.m. The decision took into account the micro-satellite constellation's surveillance mission for national security and disaster response. The actual launch took place at 12:25 p.m. The fourth launch, which carried CAS500-3, took place at 1:13 a.m.

📡A little over five hours after launch#

From King Sejong Station in Antarctica to Svalbard in the Arctic

NEONSAT 6 made its first contact with the ground station at King Sejong Station in Antarctica at around 1:08 p.m., 43 minutes after launch. By 6 p.m., two-way communication had been established with all five satellites through ground stations at KARI in Daejeon, King Sejong Station in Antarctica and Svalbard in the Arctic. After confirming these contacts, KASA and KAIST concluded that the launch had been completed successfully and began initial operations.

First-contact times for all five satellites#

In the order 6, 4, 3, 2, 5

Satellite 6 first contacted King Sejong Station in Antarctica at around 1:08 p.m. Satellite 4 then contacted King Sejong Station at around 2:42 p.m., satellite 3 contacted Svalbard in the Arctic at around 3:27 p.m., satellite 2 contacted King Sejong Station at around 4:18 p.m. and satellite 5 contacted King Sejong Station at around 5:52 p.m. All five transmitted their unique identification data and telemetry, and responded normally to commands from the ground.

Next come test images#

Health checks, in-orbit testing and the constellation mission

Initial contacts confirmed that basic conditions, including solar-panel deployment, power generation, temperature and attitude, were generally satisfactory. The satellite platforms, optical payloads, communications systems and attitude-control systems will next be checked in sequence, followed by the capture and reception of test images. Once in-orbit testing and image-quality checks are complete, the satellites will begin their constellation Earth-observation mission alongside existing satellites.

📦Ten carried, nine deployed#

Results for the secondary cubesat payloads

The secondary payloads were ten cubesats built by ten organizations, including universities, local governments and Korean companies. They comprised one satellite for verifying Korean-made devices and components, two satellites from a cubesat competition and seven selected through an open call. KARI's initial analysis of flight data found that nine of them had separated and entered their target orbit.

What the satellites went up to test#

Component verification, marine debris and fine particulate matter

The cubesats will verify the performance of Korean-made devices and components in space and investigate the low-Earth-orbit environment. They also have public-use missions, such as monitoring ocean currents in relation to marine debris around Jeju Island and analyzing trends in fine particulate matter and its causes. The developers plan to incorporate findings from actual space operations into subsequent technology development and applications.

Contact established with eight satellites#

A comprehensive announcement on October 13

Eight of the nine cubesats that separated completed contact with ground stations on launch day. These included KARI's space verification platform No. 2 for Korean-made components and satellites built by KAIST, Chosun University and Pusan National University. At the time of the announcement, attempts to contact the remaining satellite were ongoing. KASA will compile the status of the secondary payload satellites and issue a separate announcement on October 13.

🚀What five launches have built up#

From a dummy satellite to a constellation

Nuri is a three-stage launch vehicle designed, manufactured, tested and operated entirely with domestic technology. Its first stage uses four 75-ton-class engines, its second stage one 75-ton-class engine and its third stage one 7-ton-class engine. It was designed to place a 1.5-ton-class operational satellite directly into a sun-synchronous orbit at an altitude of 600 to 800 km. Its payloads have changed with each launch, from the first in 2021 to this fifth flight.

From a dummy satellite to operational satellites#

First launch in 2021, second in 2022, third in 2023

The first flight test, on October 21, 2021, carried a dummy satellite (mass simulator). The second, on June 21, 2022, carried a dummy satellite and a performance verification satellite, and KARI states that Nuri achieved a successful launch in this second flight test. The third launch, on May 25, 2023, carried NEXTSat-2 and seven cubesats, placing an operational satellite into orbit for the first time.

From thirteen satellites to fifteen#

The fourth and fifth launches

The fourth launch, on November 27, 2025, placed CAS500-3 and 12 cubesats, a total of 13 satellites, into their target orbit at an altitude of 600 km. This fifth launch carried 15 satellites, the most to date. The change was not just an increase in the number of satellites. The fifth launch also introduced a constellation launch in which five identical satellites were deployed in sequence.

🏭Taking over launch operations#

System integrator Hanwha Aerospace

Hanwha Aerospace was selected as Nuri's system integrator in October 2022. Its responsibilities have expanded with each subsequent launch. In announcing the success of the fifth launch, the government highlighted the private sector's growing experience in launch operations as a foundation for the transition to privately led launch services.

From manufacturing to operations#

An expanding role across the third, fourth and fifth launches

For the third launch, the system integrator oversaw manufacturing and jointly conducted launch operations. For the fourth, it oversaw launch-vehicle manufacturing and assembly and participated in launch operations led by KARI. Its involvement in launch operations expanded further on the fifth launch. KARI explains that the scope of participation expands according to the level of technical proficiency acquired.

The next launch and beyond#

A sixth launch in the second half of next year, then annually through 2032

KASA is preparing for a sixth launch targeted for the second half of next year. The plan is to launch Nuri at least once a year through 2032 to improve its reliability and transition to a privately led commercial launch-service system. After the fourth launch in 2025, KASA also announced that it would pursue development of a next-generation launch vehicle with greater capability than Nuri.