The rocket, KSLV-II NURI (often called simply ‘Nuri’), reached its target altitude, but failed to deliver a dummy payload into orbit. It aimed to deliver the payload into orbit 600 to 800km above Earth’s surface.
The rocket’s three stages were powered by liquid-fuel boosters built by an affiliate of South Korea‘s Hanwha conglomerate, with a cluster of four 75-tonne boosters in the first stage, another 75-tonne booster in the second, and a single 7-tonne rocket engine in the third and final stage. It is 47m in length.
The launch had been delayed by an hour because engineers needed more time to examine the rocket’s valves. There had also been concerns that strong winds and other conditions would pose challenges for a successful launch.
Streamed footage showed Nuri launching from Naro Space Centre, which is located on a small island off South Korea’s southern coast. Launch data seems to show that the third stage’s engine burned out after just 475 seconds – 50 seconds earlier than planned – and thus did not provide sufficient momentum to stabilise in orbit.
Lim Hye-sook, the science minister, explained that the first and second stages separated as planned, and the third stage ejected the payload 700km above Earth. Debris from the payload (a 1.4-tonne block of steel and aluminium) is expected to have landed in waters south of Australia. An inspection committee will be formed to analyse the failure to push the payload into orbit and map out adjustments before the rocket is next tested. It will undergo several more tests, starting with another in May 2022, before being launched with a real satellite.
Lim added: “The launch left some frustrated, but it’s meaningful that we confirmed we have obtained core technology for space launches.”
President Moon Jae-in, who watched the launch from the space centre, was relatively upbeat, stating in a televised speech: “Although (the launch) failed to achieve its objectives perfectly, it was an excellent accomplishment for a first launch. The separations of the rockets, fairings, and the dummy satellite worked smoothly. All this was done based on technology that is completely ours.”
“It’s not long before we’ll be able to launch it exactly into the target trajectory. The Korea Space Age is happening.”
South Korea has used foreign-designed rockets since the early 1990s to launch its satellites. Now, it aims to become the 10th nation to launch a satellite into orbit using its own technology. Satellite technology is considered of utmost importance to the country, which aims to send more advanced military and communications satellites into orbit to offset hostility from its northern neighbour. The country also hopes to deliver a probe to the Moon by 2030.