South Korea’s KSLV-2 rocket launches seven satellites, one unaccounted for

SEOUL, South Korea — South Korea’s KSLV-2 rocket put seven satellites, including one equipped with synthetic aperture radar, into sun-synchronous orbit May 25, although an eighth cubesat is believed to have not deployed properly.

The rocket lifted off at the planned time of 5:24 a.m. Eastern from the Naro Space Center. Live footage showed the 47.2-meter rocket, emblazoned with South Korea’s flag, soaring into the air with bright yellow flames shooting out of its engines.

It was the third launch of the kerosene and liquid oxygen-fueled three-stage rocket since its partially successful debut in October 2021. The second launch in June 2022 successfully put a 1.3-ton dummy payload and a 162-kilogram performance test satellite into low Earth orbit.

Despite the setback with one cubesat, science minister Lee Jong-ho referred to the launch as “successful” in a televised press conference held about 90 minutes after liftoff. “It would take some time to know what happened” to the cubesat, he said. The minister said the primary payload, named NEXTSat-2, had exchanged signals with a ground station in Antarctica and the six others are expected to follow suit in the coming hours.

“Following the success of the second launch last year, we reaffirmed the rocket’s performance and reliability,” the minister said.

President Yoon Suk-yeol hailed the launch as a “significant milestone,” signifying South Korea’s emergence as a major space power, according to the presidential office.

The first-stage booster, powered by a cluster of four KRE-075 engines, separated about two minutes after liftoff. The separation of its payload fairing took place 109 seconds later, followed by the second stage booster with a single KRE-075 engine 38 seconds later, according to the science ministry. The third stage, with a KRE-007 engine, pushed the payload to the intended orbit of 550 kilometers above the Earth and started deploying the satellites about 13 minutes after liftoff.

The primary payload was NEXTSat-2, a 180-kilogram technology demonstration satellite developed by the Korea Advanced Institute of Science and Technology (KAIST). It hosts a set of scientific payloads, including a KAIST-developed synthetic aperture radar that can produce imagery with five-meter resolution and a swath width of 40 kilometers.

The six smaller satellites successfully deployed are JLC-101-v1-2, a four-kilogram Earth-observation technology demonstration cubesat; Lumir-T1, a 10-kilogram cosmic radiation monitoring cubesat; KSAT3U, a six-kilogram earth observation and weather monitoring cubesat; and three 6U cubesats for the SNIPE constellation, developed by the Korea Astronomy and Space Science Institute. The troubled cubesat is the fourth satellite of that constellation, designed to orbit in formation to identify temporal and spatial variations of small-scale plasma structures in the ionosphere and magnetosphere. It is not known yet if the trouble would affect the constellation’s performance.

The launch was initially scheduled for May 24, but was delayed by one day due to a technical glitch. South Korea plans to conduct three more KSLV-2 launches through 2027 to improve the rocket’s technical reliability.

Meanwhile, South Korea is developing a next-generation launch vehicle, KSLV-3. The kerosene and liquid oxygen-fueled two-stage vehicle is expected to debut in 2030. Its first stage will have a cluster of five 100-ton-thrust multi-stage combustion cycle engines, and the upper stage with two 10-ton-thrust multi-stage combustion cycle engines. The two engines and rocket hardware will be developed by the state-funded Korea Aerospace Research Institute (KARI) in collaboration with an industry partner that will be selected by September.

The KSLV-3 will be capable of delivering up to 10 tons of payload to low Earth orbit; 7 tons to sun-synchronous orbit; 3.7 tons to geostationary transfer orbit; and 1.8 tons to lunar transfer orbit. South Korea plans to launch a domestically developed robotic lunar lander on KSLV-3 by 2032.