Source: Privy Council No. 10
South Korea's first truly domestically produced rocket, nuri, was launched on October 21 and failed to put the satellite into orbit, and South Korea lamented that it was "only one step away" from the dream of a space power.
However, after the relevant investigation report was released on December 29, the outside world was surprised to find that the rocket had major low-level errors in its innate design, and the launch failure was not an accident, and even some experts asserted that "it should be fortunate that it did not explode in flight."
What kind of low-level errors are going on?
South Korea's "Chosun Ilbo" said on December 30 that the South Korean Ministry of Science and Technology Information and Communications and the South Korean Aerospace Research Institute passed the audit results of the "Nuri Launch Investigation Committee" on the 29th and found that the rocket had major defects in the design.
Preliminary investigations concluded that the reason for the failure of the Nuri test was that the three-stage rocket engine ended burning earlier than originally planned. But this time, experts found that the rocket engine shut down early was due to the loosening of the helium tank fixture in the oxidant tank of the three-stage rocket, which crashed everywhere during the flight, causing cracks inside the tank and eventually oxidant leakage.
But the key question is, why is the fixture loose? Originally, the rocket was designed to consider only the parameter setting of the fixture in the stationary state, but the rocket will appear "overweight" when accelerating and rising, especially in the first stage of flight, which will produce a huge acceleration equivalent to 4.3G.
It was the neglect of such a junior high school physics knowledge point that the fixture that was not strong enough was loosened, which eventually led to the failure of the Nuri number worth 1,957.2 billion won (about 10.5 billion yuan) in South Korea.
A researcher at the Korea Institute of Aerospace Sciences said: "After the launch, the South Korean government said that the entire flight process of Nuri was normal, but the simulation satellite failed to successfully enter orbit, but from the results of the investigation, the rocket did not explode in the middle is already fortunate." ”
As a result, in order to strengthen the fixed parts of the helium tank and the structure of the oxidant tank, the second launch of the Nuri, which was scheduled for May next year, is expected to be postponed until the second half of next year.
Previously, the Korea Aerospace Research Institute believed that the difficulties of the rocket focused on the more complex structure of the first stage rocket, so the design of the third stage was neglected.
The hard lesson also proves that "small mistakes in the development of the universe can also lead to huge failures." ”
From this point of view, China's aerospace Long March series rockets can achieve the amazing results of all 48 launches this year, which is indeed worthy of our pride!