It’s not rocket science

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It’s not rocket science

Published: 02 Jan. 2022, 19:54 Updated: 03 Jan. 2022, 12:32

An investigation into the failed mission of Nuri 1, the first South Korean space rocket, on Oct. 21 found negligence in the failure to identify a design error. According to the results of a probe by a joint committee of the Ministry of Science and ICT and the Korea Aerospace Research Institute (KARI), the early shutdown of the third-stage engine that prevented a dummy satellite from safely reaching orbit was caused by an internal helium tank that came loose from an anchoring device.

A helium tank serves to sustain the internal pressure in the oxidizer tank. The leak lessened the power in oxidizer tank, causing the shut-down of the third-stage engine needed to propel the rocket to sustain the speed and altitude necessary to carry out the mission.

The flight study showed that abnormal vibration was sensed 36 seconds after the launch and the oxidizer tank began to lose pressure 67 seconds into the flight. Since the first-stage engine’s life is 124 seconds, the launch had been unsuccessful even from the early stage. It is surprising that the rocket did not explode earlier.

The KARI attributes the fault to the difference in the structures of the tank in the third-stage engine. Unlike the tanks in the first two stages, which are longer cylinder-type,s the third tank is rounder. The helium tanks going into the third tank differed from the first two stages. Fixing the tanks in the oxidizer tank had been erroneous, but no one was able to point it out.

The first self-developed rocket launch failed because of a design error in components. The conclusion suggests there had been no inner and outside eyes to double-check and discover errors in the final stage.

The 1986 Space Shuttle Challenger disaster, which caused the death of the entire seven-member crew soon after the blast-off, originated with two redundant O-ring seals, which were pointed out by working-level officials but ignored by the higher hierarchy.

The Korea Space Launch Vehicle-11 project has five more launches to go. The KARI, which has been devoted to achieving the country’s rocket launch, into space must go back to the basics and must not neglect each step, from every component and design to the final review.