South Korea’s KSLV-2 Rocket Delivers Payloads To Orbit

South Korea’s domestically developed KSLV-2 “Nuri” rocket successfully placed six payloads into low Earth orbit Tuesday, after lifting off from from Naro Space Center at 4 PM KST. This follows an earlier attempt in October which failed to reach orbit after the booster’s third stage engine shutdown prematurely. The flight followed an initial trajectory over the East China Sea, after which the upper stage steered out towards the Philippine Sea, finally placing the payload in the desired orbital inclination of 98 degrees. This less-than-ideal path wasted energy, but ensured that the first and second stages fell into the ocean and not onto people. Success was confirmed shortly after launch as the vehicle passed over South Korea’s King Sejong Station in Antarctica.

The payload on this test flight was primarily a mass simulator of 1.3 metric tons, but a small Performance Verification Satellite (PVSAT) was included, for a grand total of 1.5 metric tons. The PVSAT itself monitors vehicle performance, but also serves as a carrier for four CubeSats. These were developed by engineering teams at various local universities and will be deployed in the coming days.

If you’re inclined to track these, the launch has been given COSPAR ID 2022-065 and the first three objects (third stage, dummy mass, and PVSAT) have been assigned the NORAD catalog numbers 52894, 52895, and 52896. It’s too early to tell which is which at this point, but as more data about their respective orbits are collected, it should be possible to tell them apart. The next four catalog numbers, 52897 – 52900, have been reserved for the CubeSats once they are released.

With this launch, South Korea has become the 10th nation to put a payload into space using its own domestic technology, and the 7th to loft a payload of more than one ton to orbit — joining the ranks of the United States, Russia, Japan, China, France, and India.

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South Korean KSLV-2 Nuri Rocket Almost Orbits

There was a bit of excitement recently at the Naro Space Center on Outer Naro Island, just off the southern coast of the Korea Peninsula. The domestically developed South Korean Nuri rocket departed on its inaugural flight from launch pad LB-2 at 5pm in the afternoon on Thursday, 21 Oct. The previous launch in the KSLV-2 program from this facility was in 2018, when a single-stage Test Launch Vehicle was successfully flown and proved out the basic vehicle and its KRE-075 engines.

This final version of the three-stage Nuri rocket, formally known as Korean Space Launch Vehicle-II (KSLV-2), is 47.2 m long and 3.5 m in diameter. The first stage is powered by a cluster of four KRE-075 sea-level engines having 3 MN of thrust. The second stage is a single KRE-075 vacuum engine with 788 kN thrust, and the final stage is a KRE-007 vacuum engine with 69 kN thrust (all these engines are fueled by Jet-A / LOX). In this maiden flight, the first two stages performed as expected, but something went wrong when the third stage shut off prematurely and failed to gain enough velocity to put the 1400 kg dummy satellite into orbit.

A committee formed to investigate the flight failure convened this week, and issued a statement after a preliminary review of the collected telemetry data. So far, all indications point to a drop in oxidizer tank pressure in the third stage. This could be the result of a leak in the tank itself or the associated plumbing. They will also investigate whether a sensor or other failure in the tank pressurization control system could be at fault. A second launch is currently scheduled for May of next year. Check out [Scott Manley]’s video below the break, where he discusses the launch itself and some history of South Korea’s space program.

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