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The success of today's (21st) launch will be decided 16 minutes after launch.



Reporter Seo Dong-gyun will explain in detail what is different from the first launch of the 'Nuri', which started today's second launch, and what is the post-launch process.



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length of 47.2m and the height of a 15-story apartment building, the 'Nuriho' is a three-stage projectile weighing 200 tons.



Up to this point, it is the same as in the first launch, but the inside of the projectile and the way it is carried are different.



In the last launch, a model satellite was loaded, but this time, a performance verification satellite weighing 162.5 kg is loaded.



The three-stage rocket, which was the cause of the failure of the first launch, was also supplemented through extensive investigation.



The reason was that the liquid oxygen tank was cracked as the helium tank was torn off, but this time, the helium tank was fixed by changing the three-stage internal design.



Also, on the 15th, the sensor of the first stage oxidizer tank, which caused a signal abnormality, was replaced with the part used for the third launch, and inspection was completed before launch.



So let's take a look at how the changed Nuri will fly into space.



Let's take a look at the first stage rocket, which is the most important.



Four 75-ton engines capable of lifting 50 medium-sized cars are attached to the first stage, and the so-called 'clustering' technology moves the four as precisely as one to produce 300-ton-class power.



Using this force, it overcomes air resistance and gravity, and climbs up to 59 km above the ground.



Upon reaching the target, the first stage rocket, which weighs 60% of the fuselage weight, is discarded.



From this point on, the second stage rocket is in operation, and it is the same as the 75 ton engine attached to the first stage.



Next, a device called the fairing at the top of the rocket is removed.



It is sharp like a pencil to minimize air resistance and protect payloads such as satellites from frictional heat.



After the 2nd engine is disconnected, the 3rd engine will ignite last.



When the 3rd stage equipped with a 7-ton engine reaches the target altitude of 700 km, the Nuri mission is completed.



Success or failure of a challenge over 10 years will be decided 16 minutes after launch.