SEOUL, South Korea – The failed debut in October South Korean KSLV-2 rocket is blamed on improperly anchored helium tanks inside the top stage of the three-stage rocket.
The kerosene and liquid oxygen-powered KSLV-2, South Korea’s first fully domestic rocket, performed well during the early stages of the Oct. 21 test flight, but dropped its dummy payload into orbit unbearable when his upper stage engine stopped for 46 seconds. early.
A failure investigation by the Korea Aerospace Research Institute (KARI) concluded that poorly designed structures allowed the helium tanks inside the upper stage to come loose during flight, resulting in a leak that deprived the Fully domestic liquid oxygen rocket engine KRE-007.
“The support structures containing the helium tanks inside the third stage oxidation tank were not properly designed to account for a force called buoyancy,” KARI said in a declaration of December 29. Buoyancy, the upward force exerted by a fluid pushing an object, increases with the altitude of a rocket, which has not been taken into account, according to KARI.
The helium tanks with the faulty anchors were inside the upper stage oxidant tank, which was filled with liquid oxygen needed to ignite the rocket. As the helium tanks loosened, they disrupted the piping inside the oxidizer tank and caused liquid oxygen to leak, causing the ignition to stop prematurely, KARI explained.
“We apologize for not anticipating the increasing push that has occurred in the Nuri acceleration process,” said Choi Hwan-seok, KARI vice president and head of the investigation team, saying reference to the Korean nickname of KSLV-2. âWe are going to correct the problem by strengthening the anchorages of the helium tank and the structure of the oxidant tank. “
KARI officials said it would take time to resolve the issue, saying the KSLV-2’s second test flight, scheduled for May 2022, could be delayed.
KSLV-2 – the development of which cost South Korea an estimated 2,000 billion won ($ 1.8 billion) to develop – is the first step in South Korea’s ambitious space programs, including the the country’s first robotic lunar lander launched on a nationally developed rocket by 2030.
The rocket is the successor to the KSLV-1, a two-stage rocket with a Russian-made main stage. The KSLV-1 suffered back-to-back failures in 2009 and 2010 before finally putting a 100 kilogram satellite into orbit in 2013.